Vehicular Electrical System with Crash Sensors and Occupant Protection Systems

ABSTRACT

Electrical system in a vehicle includes crash sensor systems each arranged to sense a crash involving the vehicle and occupant protection systems each including an occupant protection device arranged to protect an occupant in the event of a crash involving the vehicle. The crash sensor system(s) and the occupant protection system(s) are connected to a bus and supplied with power by the bus and communication through the bus. Each occupant protection device is actuated in the event of a crash involving the vehicle as sensed by a crash sensor system. Each occupant protection system may include a power supply for providing power to enable actuation of the occupant protection device, diagnostic circuitry for self-diagnosis, an occupant sensor and a controller for controlling actuation of the occupant protection device based on a signal received from a crash sensor system over the bus, and data from the occupant sensor.

CROSS REFERENCE TO RELATED APPLICATIONS

This application is a continuation of U.S. patent application Ser. No.11/851,167 filed Sep. 6, 2007 which is:

1. a continuation-in-part (CIP) of U.S. patent application Ser. No.11/082,739 filed Mar. 17, 2005 which is:

-   -   A. a CIP of U.S. patent application Ser. No. 10/701,361 filed        Nov. 4, 2003, now U.S. Pat. No. 6,988,026, which is:        -   1. a CIP of U.S. patent application Ser. No. 09/925,062            filed Aug. 8, 2001, now U.S. Pat. No. 6,733,036, which is:            -   a) a CIP of U.S. patent application Ser. No. 09/767,020                filed Jan. 23, 2001, now U.S. Pat. No. 6,533,316, which                is a CIP of U.S. patent application Ser. No. 09/073,403                filed May 6, 1998, now U.S. Pat. No. 6,179,326, which is                a CIP of U.S. patent application Ser. No. 08/550,217                filed Oct. 30, 1995, now abandoned; and            -   b) a CIP of U.S. patent application Ser. No. 09/356,314                filed Jul. 16, 1999, now U.S. Pat. No. 6,326,704, which                is a CIP of U.S. patent application Ser. No. 08/947,661                filed Oct. 9, 1997, now abandoned, which claims domestic                priority under 35 U.S.C. §119(e) of U.S. provisional                patent application Ser. No. 60/028,046 filed Oct. 9,                1996, now expired; and        -   2. a CIP of U.S. patent application Ser. No. 10/043,557            filed Jan. 11, 2002, now U.S. Pat. No. 6,905,135, which is a            CIP of U.S. patent application Ser. No. 09/925,062 filed            Aug. 8, 2001, now U.S. Pat. No. 6,733,036, the history of            which is set forth above; and    -   B. a CIP of U.S. patent application Ser. No. 11/039,129 filed        Jan. 19, 2005, now U.S. Pat. No. 7,082,359 which is a divisional        of U.S. patent application Ser. No. 10/701,361 filed Nov. 4,        2003, now U.S. Pat. No. 6,988,026, the history of which is set        forth above;

2. a CIP of U.S. patent application Ser. No. 11/131,623 filed May 18,2005 which is a CIP of U.S. patent application Ser. No. 10/043,557 filedJan. 11, 2002, now U.S. Pat. No. 6,905,135, the history of which is setforth above;

3. a CIP of U.S. patent application Ser. No. 11/278,188 filed Mar. 31,2006 which is a continuation of U.S. patent application Ser. No.11/220,139 filed Sep. 6, 2005, now U.S. Pat. No. 7,103,460, which is aCIP of U.S. patent application Ser. No. 11/120,065 filed May 2, 2005,now abandoned;

4. a CIP of U.S. patent application Ser. No. 11/421,500 filed Jun. 1,2006 which is a CIP of U.S. patent application Ser. No. 11/220,139 filedSep. 6, 2005, now U.S. Pat. No. 7,103,460, the history of which is setforth above;

5. a CIP of U.S. patent application Ser. No. 11/421,554 filed Jun. 1,2006 which is a CIP of U.S. patent application Ser. No. 11/220,139 filedSep. 6, 2005, now U.S. Pat. No. 7,103,460, the history of which is setforth above;

6. a CIP of U.S. patent application Ser. No. 11/464,288 filed Aug. 14,2006 which is a CIP of U.S. patent application Ser. No. 11/220,139 filedSep. 6, 2005, now U.S. Pat. No. 7,103,460, the history of which is setforth above;

7. a CIP of U.S. patent application Ser. No. 11/470,061 filed Sep. 5,2006 which is a CIP of U.S. patent application Ser. No. 11/220,139 filedSep. 6, 2005, now U.S. Pat. No. 7,103,460, the history of which is setforth above.

All of the references, patents and patent applications that are referredto herein and in the parent applications are incorporated by referencein their entirety as if they had each been set forth herein in full.Note that this application is one in a series of applications coveringsafety and other systems for vehicles and other uses. The disclosureherein goes beyond that needed to support the claims of the particularinvention set forth herein. This is not to be construed that theinventors are releasing the unclaimed disclosure and subject matter intothe public domain. Rather, it is intended that patent applications havebeen or will be filed to cover all of the subject matter disclosed belowand in the current assignee's granted and pending applications. Alsoplease note that the terms frequently used below “the invention” or“this invention” is not meant to be construed that there is only oneinvention being discussed. Instead, when the terms “the invention” or“this invention” are used, it is referring to the particular inventionbeing discussed in the paragraph where the term is used.

FIELD OF THE INVENTION

The present invention relates generally to arrangements and techniquesfor managing vehicle diagnostic information at least partly at locationsremote from the vehicle.

There are numerous apparatus, systems and methods described anddisclosed herein. Many combinations of these are described but in orderto conserve space the inventors have not described all combinations andpermutations of these apparatus, systems and methods, however, theinventors intend that each and every such combination and permutation isan invention to be considered disclosed by this disclosure. Theinventors further intend to file divisional, continuation andcontinuation-in-part applications to cover many of these combinationsand permutations, if necessary.

BACKGROUND OF THE INVENTION

A detailed background of the invention is found in the parentapplications, e.g., U.S. patent application Ser. No. 09/925,062 and U.S.patent application Ser. No. 09/767,020, incorporated by referenceherein.

The definitions set forth in section 5.0 of the Background of theInvention section of the parent '139 application are also incorporatedby reference herein.

All of the patents, patent applications, technical papers and otherreferences referenced in the parent '139 application and herein areincorporated herein by reference in their entirety.

OBJECTS AND SUMMARY OF THE INVENTION

It is an object of the present invention to provide new and improvedvehicular electrical systems including crash sensors and occupantprotection or restraint systems.

In order to achieve this object and others, a first embodiment of anelectrical system in a vehicle in accordance with the invention includesone or more crash sensor systems each arranged to sense a crashinvolving the vehicle, one or more occupant protection systems eachincluding an occupant protection device arranged to protect an occupantin the event of a crash involving the vehicle and a single busconsisting of a pair of wires. The crash sensor system(s) and theoccupant protection system(s) are connected to the bus and supplied withpower by the bus and communication through the bus. Each occupantprotection device is actuated in the event of a crash involving thevehicle as sensed by one or more of the crash sensor systems.

In one embodiment, each occupant protection system comprises a powersupply for providing power to enable actuation of the occupantprotection device. It may also include a housing in which the occupantprotection device is arranged, in which case, the power supply may be acapacitor or other type of energy storage element arranged in thehousing.

Additionally or alternatively, each occupant protection system maycomprise an occupant sensor arranged to obtain data about occupancy ofthe vehicle for use in determining actuation of the occupant protectiondevice. For example, when the occupant protection device is an airbag,each occupant protection systems may comprise a module including anoccupant position sensor arranged to obtain data about the position ofan occupant to be protected upon inflation of the airbag, and acontroller coupled to the occupant position sensor for controllingdeployment and inflation of the airbag based on the position of theoccupant. The controller may be arranged in the module, adjacent themodule and/or proximate the module.

The bus may be arranged to provide a signal indicative of a crashinvolving the vehicle as obtained from one or more of the crash sensorsystems. Each occupant protective system may be arranged to receive thesignal and independently determine whether to actuate the occupantprotection device therein.

In one embodiment, each occupant protection system comprises diagnosticelectronics for diagnosing functionality of the occupant protectionsystem, e.g., the ability of the occupant protection device to bedeployed, inflated or otherwise actuated. A central diagnostic modulemay be connected to the bus with the diagnostic electronics of eachoccupant protection system being arranged to provide an indication ofthe functionality thereof to the central diagnostic module. The centraldiagnostic module can be arranged to provide an indication of thefunctionality of all of occupant protection systems, e.g., a malfunctionwith one or more of the occupant protection systems, to a displayvisible to an occupant of the vehicle.

In one embodiment, each crash sensor system generates and sends a codedsignal over the bus, e.g., to each occupant protection system, the codedsignal being indicative of a sensed crash condition.

When there are a plurality of occupant protection systems, each may beassigned an address and the bus transfers data in the form of messageseach having an address of at least one occupant protection systems suchthat only that occupant protection system assigned to the address isresponsive to the message having the address. To this end, each occupantprotection system may determine whether messages on the bus include theaddress assigned thereto.

Another embodiment of an electrical system in a vehicle in accordancewith the invention includes a plurality of crash sensor systems eacharranged to sense a crash involving the vehicle, a plurality of occupantprotection systems each including an occupant protection device arrangedto protect an occupant in the event of a crash involving the vehicle,and a first bus. A discrete portion of the crash sensor systems and adiscrete portion of the occupant protection systems are coupled to thefirst bus and supplied with power by the first bus and communicationthrough the first bus. Each occupant protection device is actuatable inthe event of a crash involving the vehicle as sensed by one of the crashsensor systems. Further, the electrical system includes a second bus. Adiscrete portion of the crash sensor systems and a discrete portion ofthe occupant protection systems, i.e., not those coupled to the firstbus, are coupled to the second bus and supplied with power by the secondbus and communication through the second bus. Each occupant protectiondevice is actuatable in the event of a crash involving the vehicle assensed by one of the crash sensor systems. Accordingly, in thisembodiment, each crash sensor system and each occupant protectionsystems is either coupled to the first bus or to the second bus.

The same variations described above for the first embodiment areapplicable in this embodiment as well.

Other objects and advantages of the present claimed invention andinventions disclosed below are set forth in the '139 application andothers will become apparent from the following description of thepreferred embodiments taken in conjunction with the accompanyingdrawings.

BRIEF DESCRIPTION OF THE DRAWINGS

The following drawings are illustrative of embodiments of the systemsdeveloped or adapted using the teachings of these inventions and are notmeant to limit the scope of the invention as encompassed by the claims.

FIG. 1 is a schematic illustration of a generalized component withseveral signals being emitted and transmitted along a variety of paths,sensed by a variety of sensors and analyzed by the diagnostic module inaccordance with the invention and for use in a method in accordance withthe invention.

FIG. 2 is a schematic of one pattern recognition methodology known as aneural network which may be used in a method in accordance with theinvention.

FIG. 3 is a schematic of a vehicle with several components and severalsensors and a total vehicle diagnostic system in accordance with theinvention utilizing a diagnostic module in accordance with the inventionand which may be used in a method in accordance with the invention.

FIG. 4 is a flow diagram of information flowing from various sensorsonto the vehicle data bus and thereby into the diagnostic module inaccordance with the invention with outputs to a display for notifyingthe driver, and to the vehicle cellular phone for notifying anotherperson, of a potential component failure.

FIG. 5 is an overhead view of a roadway with vehicles and a SAW roadtemperature and humidity monitoring sensor.

FIG. 5A is a detail drawing of the monitoring sensor of FIG. 5.

FIG. 6 is a perspective view of a SAW system for locating a vehicle on aroadway, and on the earth surface if accurate maps are available, andalso illustrates the use of a SAW transponder in the license plate forthe location of preceding vehicles and preventing rear end impacts.

FIG. 7 is a partial cutaway view of a section of a fluid reservoir witha SAW fluid pressure and temperature sensor for monitoring oil, water,or other fluid pressure.

FIG. 8 is a perspective view of a vehicle suspension system with SAWload sensors.

FIG. 8A is a cross section detail view of a vehicle spring and shockabsorber system with a SAW torque sensor system mounted for measuringthe stress in the vehicle spring of the suspension system of FIG. 8.

FIG. 8B is a detail view of a SAW torque sensor and shaft compressionsensor arrangement for use with the arrangement of FIG. 8.

FIG. 9 is a cutaway view of a vehicle showing possible mountinglocations for vehicle interior temperature, humidity, carbon dioxide,carbon monoxide, alcohol or other chemical or physical propertymeasuring sensors.

FIG. 10A is a perspective view of a SAW tilt sensor using four SAWassemblies for tilt measurement and one for temperature.

FIG. 10B is a top view of a SAW tilt sensor using three SAW assembliesfor tilt measurement each one of which can also measure temperature.

FIG. 11 is a perspective exploded view of a SAW crash sensor for sensingfrontal, side or rear crashes.

FIG. 12 is a perspective view with portions cutaway of a SAW basedvehicle gas gage.

FIG. 12A is a top detailed view of a SAW pressure and temperaturemonitor for use in the system of FIG. 12.

FIG. 13A is a schematic of a prior art deployment scheme for an airbagmodule.

FIG. 13B is a schematic of a deployment scheme for an airbag module inaccordance with the invention.

FIG. 14 is a schematic of a vehicle with several accelerometers and/orgyroscopes at preferred locations in the vehicle.

FIG. 15A illustrates a driver with a timed RFID standing with groceriesby a closed trunk.

FIG. 15B illustrates the driver with the timed RFID 5 seconds after thetrunk has been opened.

FIG. 15C illustrates a trunk opening arrangement for a vehicle inaccordance with the invention.

FIG. 16A is a view of a view of a SAW switch sensor for mounting on orwithin a surface such as a vehicle armrest.

FIG. 16B is a detailed perspective view of the device of FIG. 16A withthe force-transmitting member rendered transparent.

FIG. 16C is a detailed perspective view of an alternate SAW device foruse in FIGS. 16A and 16B showing the use of one of two possibleswitches, one that activates the SAW and the other that suppresses theSAW.

FIG. 17A is a detailed perspective view of a polymer and mass on SAWaccelerometer for use in crash sensors, vehicle navigation, etc.

FIG. 17B is a detailed perspective view of a normal mass on SAWaccelerometer for use in crash sensors, vehicle navigation, etc.

FIG. 18 is a view of a prior art SAW gyroscope that can be used withthis invention.

FIGS. 19A, 19B and 19C are block diagrams of three interrogators thatcan be used with this invention to interrogate several differentdevices.

FIG. 20 is a side view with parts cutaway and removed of a vehicleshowing the passenger compartment containing a rear facing child seat onthe front passenger seat and a preferred mounting location for anoccupant and rear facing child seat presence detector.

FIG. 21 is a partial cutaway view of a vehicle driver wearing a seatbeltwith SAW force sensors.

FIGS. 22A, 22B, 22C and 22D are different views of an automotiveconnector for use with a coaxial electrical bus for a motor vehicleillustrating the teachings of this invention.

FIG. 23 illustrates a strain gage on a bolt weight sensor.

FIGS. 24A, 24B, 24C, 24D and 24E are views of occupant seat weightsensors using a slot spanning SAW strain gage and other strainconcentrating designs.

FIG. 25 is a side view with parts cutaway and removed showingschematically the interface between the vehicle interior monitoringsystem of this invention and the vehicle cellular communication system.

FIG. 26 is a diagram of one exemplifying embodiment of the invention.

FIG. 27 is a perspective view of a carbon dioxide SAW sensor formounting in the trunk lid for monitoring the inside of the trunk fordetecting trapped children or animals.

FIG. 27A is a detailed view of the SAW carbon dioxide sensor of FIG. 27.

FIG. 28 is a schematic view of overall telematics system in accordancewith the invention.

FIG. 29 is a perspective view of the combination of an occupant positionsensor, diagnostic electronics and power supply and airbag moduledesigned to prevent the deployment of the airbag if the seat isunoccupied.

FIG. 30 shows the application of a preferred implementation of theinvention for mounting on the rear of front seats to provide protectionfor rear seat occupants.

FIG. 31 is another implementation of the invention incorporating theelectronic components into and adjacent the airbag module.

DETAILED DESCRIPTION OF THE INVENTION

1.1 General Diagnostics and Prognostics

The output of a diagnostic system is generally the present condition ofthe vehicle or component. However the vehicle operator wants to repairthe vehicle or replace the component before it fails, but a diagnosissystem in general does not specify when that will occur. Prognostics isthe process of determining when the vehicle or a component will fail. Atleast one of the inventions disclosed herein in concerned withprognostics. Prognostics can be based on models of vehicle or componentdegradation and the effects of environment and usage. In this regard itis useful to have a quantitative formulation of how the componentdegradation depends on environment, usage and current componentcondition. This formulation may be obtained by monitoring condition,environment and usage level, and by modeling the relationships withstatistical techniques or pattern recognition techniques such as neuralnetworks, combination neural networks and fuzzy logic. In some cases, itcan also be obtained by theoretical methods or from laboratoryexperiments.

A preferred embodiment of the vehicle diagnostic and prognostic unitdescribed below performs the diagnosis and prognostics, i.e., processesthe input from the various sensors, on the vehicle using, for example, aprocessor embodying a pattern recognition technique such as a neuralnetwork. The processor thus receives data or signals from the sensorsand generates an output indicative or representative of the operatingconditions of the vehicle or its component. A signal could thus begenerated indicative of an under-inflated tire, or an overheatingengine.

For the discussion below, the following terms are defined as follows:

The term “component” as used herein generally refers to any part orassembly of parts which is mounted to or a part of a motor vehicle andwhich is capable of emitting a signal representative of its operatingstate. The following is a partial list of general automobile and truckcomponents, the list not being exhaustive:

Engine; transmission; brakes and associated brake assembly; tires;wheel; steering wheel and steering column assembly; water pump;alternator; shock absorber; wheel mounting assembly; radiator; battery;oil pump; fuel pump; air conditioner compressor; differential gearassembly; exhaust system; fan belts; engine valves; steering assembly;vehicle suspension including shock absorbers; vehicle wiring system; andengine cooling fan assembly.

The term “sensor” as used herein generally refers to any measuring,detecting or sensing device mounted on a vehicle or any of itscomponents including new sensors mounted in conjunction with thediagnostic module in accordance with the invention. A partial,non-exhaustive list of sensors that are or can be mounted on anautomobile or truck is:

Airbag crash sensor; microphone; camera; chemical sensor; vapor sensor;antenna, capacitance sensor or other electromagnetic wave sensor; stressor strain sensor; pressure sensor; weight sensor; magnetic field sensor;coolant thermometer; oil pressure sensor; oil level sensor; air flowmeter; voltmeter; ammeter; humidity sensor; engine knock sensor; oilturbidity sensor; throttle position sensor; steering wheel torquesensor; wheel speed sensor; tachometer; speedometer; other velocitysensors; other position or displacement sensors; oxygen sensor; yaw,pitch and roll angular sensors; clock; odometer; power steering pressuresensor; pollution sensor; fuel gauge; cabin thermometer; transmissionfluid level sensor; gyroscopes or other angular rate sensors includingyaw, pitch and roll rate sensors; accelerometers including single axis,dual axis and triaxial accelerometers; an inertial measurement unit;coolant level sensor; transmission fluid turbidity sensor; brakepressure sensor; tire pressure sensor; tire temperature sensor, tireacceleration sensor; GPS receiver; DGPS receiver; and coolant pressuresensor.

The term “signal” as used herein generally refers to any time-varyingoutput from a component including electrical, acoustic, thermal,electromagnetic radiation or mechanical vibration.

Sensors on a vehicle are generally designed to measure particularparameters of particular vehicle components. However, frequently thesesensors also measure outputs from other vehicle components. For example,electronic airbag crash sensors currently in use contain one or moreaccelerometers for determining the accelerations of the vehiclestructure so that the associated electronic circuitry of the airbagcrash sensor can determine whether a vehicle is experiencing a crash ofsufficient magnitude so as to require deployment of the airbag. Eachaccelerometer continuously monitors the vibrations in the vehiclestructure regardless of the source of these vibrations. If a wheel isout of balance, or if there is extensive wear of the parts of the frontwheel mounting assembly, or wear in the shock absorbers, the resultingabnormal vibrations or accelerations can, in many cases, be sensed by acrash sensor accelerometer. There are other cases, however, where thesensitivity or location of an airbag crash sensor accelerometer is notappropriate and one or more additional accelerometers or gyroscopes maybe mounted onto a vehicle for the purposes of this invention. Someairbag crash sensors are not sufficiently sensitive accelerometers orhave sufficient dynamic range for the purposes herein.

For example, a technique for some implementations of an inventiondisclosed herein is the use of multiple accelerometers and/ormicrophones that will allow the system to locate the source of anymeasured vibrations based on the time of flight, time of arrival,direction of arrival and/or triangulation techniques. Once a distributedaccelerometer installation, or one or more IMUs, has been implemented topermit this source location, the same sensors can be used for smartercrash sensing as it can permit the determination of the location of theimpact on the vehicle. Once the impact location is known, a highlytailored algorithm can be used to accurately forecast the crash severitymaking use of knowledge of the force vs. crush properties of the vehicleat the impact location.

Every component of a vehicle can emit various signals during its life.These signals can take the form of electromagnetic radiation, acousticradiation, thermal radiation, vibrations transmitted through the vehiclestructure and voltage or current fluctuations, depending on theparticular component. When a component is functioning normally, it maynot emit a perceptible signal. In that case, the normal signal is nosignal, i.e., the absence of a signal. In most cases, a component willemit signals that change over its life and it is these changes whichtypically contain information as to the state of the component, e.g.,whether failure of the component is impending. Usually components do notfail without warning. However, most such warnings are either notperceived or if perceived, are not understood by the vehicle operatoruntil the component actually fails and, in some cases, a breakdown ofthe vehicle occurs.

An important system and method as disclosed herein for acquiring datafor performing the diagnostics, prognostics and health monitoringfunctions makes use of the acoustic transmissions from variouscomponents. This can involve the placement of one or more microphones,accelerometers, or other vibration sensors onto and/or at a variety oflocations within the vehicle where the sound or vibrations are mosteffectively sensed. In addition to acquiring data relative to aparticular component, the same sensors can also obtain data that permitsanalysis of the vehicle environment. A pothole, for example, can besensed and located for possible notification to a road authority if alocation determining apparatus is also resident on the vehicle.

In a few years, it is expected that various roadways will have systemsfor automatically guiding vehicles operating thereon. Such systems havebeen called “smart highways” and are part of the field of intelligenttransportation systems (ITS). If a vehicle operating on such a smarthighway were to breakdown due to the failure of a component, seriousdisruption of the system could result and the safety of other users ofthe smart highway could be endangered.

When a vehicle component begins to change its operating behavior, it isnot always apparent from the particular sensors which are monitoringthat component, if any. The output from any one of these sensors can benormal even though the component is failing. By analyzing the output ofa variety of sensors, however, the pending failure can frequently bediagnosed. For example, the rate of temperature rise in the vehiclecoolant, if it were monitored, might appear normal unless it were knownthat the vehicle was idling and not traveling down a highway at a highspeed. Even the level of coolant temperature which is in the normalrange could be in fact abnormal in some situations signifying a failingcoolant pump, for example, but not detectable from the coolantthermometer alone.

The pending failure of some components is difficult to diagnose andsometimes the design of the component requires modification so that thediagnosis can be more readily made. A fan belt, for example, frequentlybegins failing as a result of a crack of the inner surface. The belt canbe designed to provide a sonic or electrical signal when this crackingbegins in a variety of ways. Similarly, coolant hoses can be designedwith an intentional weak spot where failure will occur first in acontrolled manner that can also cause a whistle sound as a small amountof steam exits from the hose. This whistle sound can then be sensed by ageneral purpose microphone, for example.

In FIG. 1, a generalized component 35 emitting several signals which aretransmitted along a variety of paths, sensed by a variety of sensors andanalyzed by the diagnostic device in accordance with the invention isillustrated schematically. Component 35 is mounted to a vehicle 52 andduring operation it emits a variety of signals such as acoustic 36,electromagnetic radiation 37, thermal radiation 38, current and voltagefluctuations in conductor 39 and mechanical vibrations 40. Varioussensors are mounted in the vehicle to detect the signals emitted by thecomponent 35. These include one or more vibration sensors(accelerometers) 44, 46 and/or gyroscopes or one or more IMUs, one ormore acoustic sensors 41, 47, electromagnetic radiation sensors 42, heatradiation sensors 43 and voltage or current sensors 45.

In addition, various other sensors 48, 49 measure other parameters ofother components that in some manner provide information directly orindirectly on the operation of component 35. Each of the sensorsillustrated in FIG. 1 can be connected to a data bus 50. A diagnosticmodule 51, in accordance with the invention, can also be attached to thevehicle data bus 50 and it can receive the signals generated by thevarious sensors. The sensors may however be wirelessly connected to thediagnostic module 51 and be integrated into a wireless power andcommunications system or a combination of wired and wirelessconnections. The wireless connection of one or more sensors to areceiver, controller or diagnostic module is an important teaching ofone or more of the inventions disclosed herein.

The diagnostic module 51 will analyze the received data in light of thedata values or patterns itself either statically or over time. In somecases, a pattern recognition algorithm as discussed below will be usedand in others, a deterministic algorithm may also be used either aloneor in combination with the pattern recognition algorithm. Additionally,when a new data value or sequence is discovered the information can besent to an off-vehicle location, perhaps a dealer or manufacturer site,and a search can be made for other similar cases and the resultsreported back to the vehicle. Also additionally as more and morevehicles are reporting cases that perhaps are also examined by engineersor mechanics, the results can be sent to the subject vehicle or to allsimilar vehicles and the diagnostic software updated automatically.Thus, all vehicles can have the benefit from information relative toperforming the diagnostic function. Similarly, the vehicle dealers andmanufacturers can also have up-to-date information as to how aparticular class or model of vehicle is performing. This telematicsfunction is discussed elsewhere herein. By means of this system, avehicle diagnostic system can predict component failures long beforethey occur and thus prevent on-road problems.

An important function that can be performed by the diagnostic systemherein is to substantially diagnose the vehicle's own problems ratherthen, as is the case with the prior art, forwarding raw data to acentral site for diagnosis. Eventually, a prediction as to the failurepoint of all significant components can be made and the owner can have aprediction that the fan belt will last another 20,000 miles, or that thetires should be rotated in 2,000 miles or replaced in 20,000 miles. Thisinformation can be displayed or reported orally or sent to the dealerwho can then schedule a time for the customer to visit the dealership orfor the dealer to visit the vehicle wherever it is located. If it isdisplayed, it can be automatically displayed periodically or when thereis urgency or whenever the operator desires. The display can be locatedat any convenient place such as the dashboard or it can be a heads-updisplay. The display can be any convenient technology such as an LCDdisplay or an OLED based display. This can permit the vehiclemanufacturer to guarantee that the owner will never experience a vehiclebreakdown provided he or she permits the dealer to service the vehicleat appropriate times based on the output of the prognostics system.

It is worth emphasizing that in many cases, it is the rate that aparameter is changing that can be as or more important than the actualvalue in predicting when a component is likely to fail. In a simple casewhen a tire is losing pressure, for example, it is a quite differentsituation if it is losing one psi per day or one psi per minute.Similarly for the tire case, if the tire is heating up at one degree perhour or 100 degrees per hour may be more important in predicting failuredue to delamination or overloading than the particular temperature ofthe tire.

The diagnostic module, or other component, can also consider situationawareness factors such as the age or driving habits of the operator, thelocation of the vehicle (e.g., is it in the desert, in the arctic inwinter), the season, the weather forecast, the length of a proposedtrip, the number and location of occupants of the vehicle etc. Thesystem may even put limits on the operation of the vehicle such asturning off unnecessary power consuming components if the alternator isfailing or limiting the speed of the vehicle if the driver is an elderlywoman sitting close to the steering wheel, for example. Furthermore, thesystem may change the operational parameters of the vehicle such as theengine RPM or the fuel mixture if doing so will prolong vehicleoperation. In some cases where there is doubt whether a component isfailing, the vehicle operating parameters may be temporarily varied bythe system in order to accentuate the signal from the component topermit more accurate diagnosis.

In addition to the above discussion there are some diagnostic featuresalready available on some vehicles some of which are related to thefederally mandated OBD-II and can be included in the general diagnosticsand health monitoring features of this invention. In typicalapplications, the set of diagnostic data includes at least one of thefollowing: diagnostic trouble codes, vehicle speed, fuel level, fuelpressure, miles per gallon, engine RPM, mileage, oil pressure, oiltemperature, tire pressure, tire temperature, engine coolanttemperature, intake-manifold pressure, engine-performance tuningparameters, alarm status, accelerometer status, cruise-control status,fuel-injector performance, spark-plug timing, and a status of ananti-lock braking system.

The data parameters within the set describe a variety of electrical,mechanical, and emissions-related functions in the vehicle. Several ofthe more significant parameters from the set are:

Pending DTCs (Diagnostic Trouble Codes)

Ignition Timing Advance

Calculated Load Value

Air Flow Rate MAF Sensor

Engine RPM

Engine Coolant Temperature

Intake Air Temperature

Absolute Throttle Position Sensor

Vehicle Speed

Short-Term Fuel Trim

Long-Term Fuel Trim

MIL Light Status

Oxygen Sensor Voltage

Oxygen Sensor Location

Delta Pressure Feedback EGR Pressure Sensor

Evaporative Purge Solenoid Duty cycle

Fuel Level Input Sensor

Fuel Tank Pressure Voltage

Engine Load at the Time of Misfire

Engine RPM at the Time of Misfire

Throttle Position at the Time of Misfire

Vehicle Speed at the Time of Misfire

Number of Misfires

Transmission Fluid Temperature

PRNDL position (1,2,3,4,5=neutral, 6=reverse)

Number of Completed OBDII Trips, and

Battery Voltage.

When the diagnostic system determines that the operator is operating thevehicle in such a manner that the failure of a component is accelerated,then a warning can be issued to the operator. For example, the drivermay have inadvertently placed the automatic gear shift lever in a lowergear and be driving at a higher speed than he or she should for thatgear. In such a case, the driver can be notified to change gears.

Managing the diagnostics and prognostics of a complex system has beentermed “System Health Management” and has not been applied to over theroad vehicles such as trucks and automobiles. Such systems are used forfault detection and identification, failure prediction (estimating thetime to failure), tracking degradation, maintenance scheduling, errorcorrection in the various measurements which have been corrupted andthese same tasks are applicable here.

Various sensors, both wired and wireless, will be discussed below.Representative of such sensors are those available from Honeywell whichare MEMS-based sensors for measuring temperature, pressure, acousticemission, strain, and acceleration. The devices are based on resonantmicrobeam force sensing technology. Coupled with a precision siliconmicrostructure, the resonant microbeams provide a high sensitivity formeasuring inertial acceleration, inclination, and vibrations. Alternatedesigns based on SAW technology lend themselves more readily to wirelessand powerless operation as discussed below. The Honeywell sensors can benetworked wirelessly but still require power.

Since this system is independent of the dedicated sensor monitoringsystem and instead is observing more than one sensor, inconsistencies insensor output can be detected and reported indicating the possibleerratic or inaccurate operation of a sensor even if this is intermittent(such as may be caused by a lose wire) thus essentially eliminating manyof the problems reported in the above-referenced article “What's Buggingthe High-Tech Car”. Furthermore, the software can be independent of thevehicle specific software for a particular sensor and system and canfurther be based on pattern recognition, to be discussed next, renderingit even less likely to provide the wrong diagnostic. Since the outputfrom the diagnostic and prognostic system herein described can be sentvia telematics to the dealer and vehicle manufacturer, the occurrence ofa sensor or system failure can be immediately logged to form a frequencyof failure log for a particular new vehicle model allowing themanufacturer to more quickly schedule a recall if a previously unknownproblem surfaces in the field.

1.2 Pattern Recognition

In accordance with at least one invention, each of the signals emittedby the sensors can be converted into electrical signals and thendigitized (i.e., the analog signal is converted into a digital signal)to create numerical time series data which is entered into a processor.Pattern recognition algorithms can be applied by the processor toattempt to identify and classify patterns in this time series data. Fora particular component, such as a tire for example, the algorithmattempts to determine from the relevant digital data whether the tire isfunctioning properly or whether it requires balancing, additional air,or perhaps replacement.

Frequently, the data entered into the pattern recognition algorithmneeds to be preprocessed before being analyzed. The data from a wheelspeed sensor, for example, might be used “as is” for determining whethera particular tire is operating abnormally in the event it is unbalanced,whereas the integral of the wheel speed data over a long time period (apreprocessing step), when compared to such sensors on different wheels,might be more useful in determining whether a particular tire is goingflat and therefore needs air. This is the basis of some tire monitorsnow on the market. Such indirect systems are not permitted as a meansfor satisfying federal safety requirements. These systems generallydepend on the comparison of the integral of the wheel speed to determinethe distance traveled by the wheel surface and that system is thencompared with other wheels on the vehicle to determine that one tire hasrelatively less air than another. Of course this system fails if all ofthe tires have low pressure. One solution is to compare the distancetraveled by a wheel with the distance that it should have traveled. Ifthe angular motion (displacement and/or velocity) of the wheel axle isknown, than this comparison can be made directly. Alternately, if theposition of the vehicle is accurately monitored so that the actualtravel along its path can be determined through a combination of GPS andan IMU, for example, then again the pressure within a vehicle tire canbe determined.

In some cases, the frequencies present in a set of data are a betterpredictor of component failures than the data itself. For example, whena motor begins to fail due to worn bearings, certain characteristicfrequencies began to appear. In most cases, the vibrations arising fromrotating components, such as the engine, will be normalized based on therotational frequency. Moreover, the identification of which component iscausing vibrations present in the vehicle structure can frequently beaccomplished through a frequency analysis of the data. For these cases,a Fourier transformation of the data can be made prior to entry of thedata into a pattern recognition algorithm. Wavelet transforms and othermathematical transformations are also made for particular patternrecognition purposes in practicing the teachings of this invention. Someof these include shifting and combining data to determine phase changesfor example, differentiating the data, filtering the data and samplingthe data. Also, there exist certain more sophisticated mathematicaloperations that attempt to extract or highlight specific features of thedata. The inventions herein contemplate the use of a variety of thesepreprocessing techniques and the choice of which one or ones to use isleft to the skill of the practitioner designing a particular diagnosticand prognostic module. Note, whenever diagnostics is used below it willbe assumed to also include prognostics.

As shown in FIG. 1, the diagnostic module 51 has access to the outputdata of each of the sensors that are known to have or potentially mayhave information relative to or concerning the component 35. This dataappears as a series of numerical values each corresponding to a measuredvalue at a specific point in time. The cumulative data from a particularsensor is called a time series of individual data points. The diagnosticmodule 51 compares the patterns of data received from each sensorindividually, or in combination with data from other sensors, withpatterns for which the diagnostic module has been programmed or trainedto determine whether the component is functioning normally orabnormally.

Important to some embodiments of the inventions herein is the manner inwhich the diagnostic module 51 determines a normal pattern from anabnormal pattern and the manner in which it decides what data to usefrom the vast amount of data available. This can be accomplished usingpattern recognition technologies such as artificial neural networks andtraining and in particular, combination neural networks as described inU.S. patent application Ser. No. 10/413,426 (Publication 20030209893).The theory of neural networks including many examples can be found inseveral books on the subject including: (1) Techniques And ApplicationOf Neural Networks, edited by Taylor, M. and Lisboa, P., Ellis Horwood,West Sussex, England, 1993; (2) Naturally Intelligent Systems, byCaudill, M. and Butler, C., MIT Press, Cambridge Mass., 1990; (3) J. M.Zaruda, Introduction to Artificial Neural Systems, West Publishing Co.,N.Y., 1992, (4) Digital Neural Networks, by Kung, S. Y., PTR PrenticeHall, Englewood Cliffs, N.J., 1993, Eberhart, R., Simpson, P., (5)Dobbins, R., Computational Intelligence PC Tools, Academic Press, Inc.,1996, Orlando, Fla., (6) Cristianini, N. and Shawe-Taylor, J. AnIntroduction to Support Vector Machines and other kernal-based learningmethods, Cambridge University Press, Cambridge England, 2000; (7)Proceedings of the 2000 6^(th) IEEE International Workshop on CellularNeural Networks and their Applications (CNNA 2000), IEEE, PiscatawayN.J.; and (8) Sinha, N. K. and Gupta, M. M. Soft Computing & IntelligentSystems, Academic Press 2000 San Diego, Calif. The neural networkpattern recognition technology is one of the most developed of patternrecognition technologies. The invention described herein frequently usescombinations of neural networks to improve the pattern recognitionprocess, as discussed in U.S. patent application Ser. No. 10/413,426.

The neural network pattern recognition technology is one of the mostdeveloped of pattern recognition technologies. The neural network willbe used here to illustrate one example of a pattern recognitiontechnology but it is emphasized that this invention is not limited toneural networks. Rather, the invention may apply any known patternrecognition technology including various segmentation techniques, sensorfusion and various correlation technologies. In some cases, the patternrecognition algorithm is generated by an algorithm-generating programand in other cases, it is created by, e.g., an engineer, scientist orprogrammer. A brief description of a particular simple example of aneural network pattern recognition technology is set forth below.

Neural networks are constructed of processing elements known as neuronsthat are interconnected using information channels called interconnectsand are arranged in a plurality of layers. Each neuron can have multipleinputs but generally only one output. Each output however is usuallyconnected to many, frequently all, other neurons in the next layer. Theneurons in the first layer operate collectively on the input data asdescribed below. Neural networks learn by extracting relationalinformation from the data and the desired output. Neural networks havebeen applied to a wide variety of pattern recognition problems includingautomobile occupant sensing, speech recognition, optical characterrecognition and handwriting analysis.

To train a neural network, data is provided in the form of one or moretime series that represents the condition to be diagnosed, which can beinduced to artificially create an abnormally operating component, aswell as normal operation. In the training stage of the neural network orother type of pattern recognition algorithm, the time series data forboth normal and abnormal component operation is entered into a processorwhich applies a neural network-generating program to output a neuralnetwork capable of determining abnormal operation of a component.

As an example, the simple case of an out-of-balance tire will be used.Various sensors on the vehicle can be used to extract information fromsignals emitted by the tire such as an accelerometer, a torque sensor onthe steering wheel, the pressure output of the power steering system, atire pressure monitor or tire temperature monitor. Other sensors thatmight not have an obvious relationship to tire unbalance (or imbalance)are also included such as, for example, the vehicle speed or wheel speedthat can be determined from the anti-lock brake (ABS) system. Data istaken from a variety of vehicles where the tires were accuratelybalanced under a variety of operating conditions also for cases wherevarying amounts of tire unbalance was intentionally introduced. Once thedata had been collected, some degree of pre-processing (e.g., time orfrequency modification) and/or feature extraction is usually performedto reduce the total amount of data fed to the neural network-generatingprogram. In the case of the unbalanced tire, the time period betweendata points might be selected such that there are at least ten datapoints per revolution of the wheel. For some other application, the timeperiod might be one minute or one millisecond.

Once the data has been collected, it is processed by the neuralnetwork-generating program, for example, if a neural network patternrecognition system is to be used. Such programs are availablecommercially, e.g., from NeuralWare of Pittsburgh, Pa. or fromInternational Scientific Research, Inc., of Panama for modular neuralnetworks. The program proceeds in a trial and error manner until itsuccessfully associates the various patterns representative of abnormalbehavior, an unbalanced tire in this case, with that condition. Theresulting neural network can be tested to determine if some of the inputdata from some of the sensors, for example, can be eliminated. In thismanner, the engineer can determine what sensor data is relevant to aparticular diagnostic problem. The program then generates an algorithmthat is programmed onto a microprocessor, microcontroller, neuralprocessor, FPGA, or DSP (herein collectively referred to as amicroprocessor or processor). Such a microprocessor appears inside thediagnostic module 51 in FIG. 1.

Once trained, the neural network, as represented by the algorithm, isinstalled in a processor unit of a motor vehicle and will now recognizean unbalanced tire on the vehicle when this event occurs. At that time,when the tire is unbalanced, the diagnostic module 51 will receiveoutput from the sensors, determine whether the output is indicative ofabnormal operation of the tire, e.g., lack of tire balance, and instructor direct another vehicular system to respond to the unbalanced tiresituation. Such an instruction may be a message to the driver indicatingthat the tire should now be balanced, as described below. The message tothe driver is provided by an output device coupled to or incorporatedwithin the module 51, e.g., an icon or text display, and may be a lighton the dashboard, a vocal tone or any other recognizable indicationapparatus. A similar message may also be sent to the dealer, vehiclemanufacturer or other repair facility or remote facility via acommunications channel between the vehicle and the dealer or repairfacility which is established by a suitable transmission device.

It is important to note that there may be many neural networks involvedin a total vehicle diagnostic system. These can be organized either inparallel, series, as an ensemble, cellular neural network or as amodular neural network system. In one implementation of a modular neuralnetwork, a primary neural network identifies that there is anabnormality and tries to identify the likely source. Once a choice hasbeen made as to the likely source of the abnormality, another, specificneural network of a group of neural networks can be called upon todetermine the exact cause of the abnormality. In this manner, the neuralnetworks are arranged in a tree pattern with each neural network trainedto perform a particular pattern recognition task.

Discussions on the operation of a neural network can be found in theabove references on the subject and are understood by those skilled inthe art. Neural networks are the most well-known of the patternrecognition technologies based on training, although neural networkshave only recently received widespread attention and have been appliedto only very limited and specialized problems in motor vehicles such asoccupant sensing (by the current assignee) and engine control (by FordMotor Company). Other non-training based pattern recognitiontechnologies exist, such as fuzzy logic. However, the programmingrequired to use fuzzy logic, where the patterns must be determine by theprogrammer, usually render these systems impractical for general vehiclediagnostic problems such as described herein (although their use is notimpossible in accordance with the teachings of the invention).Therefore, preferably the pattern recognition systems that learn bytraining are used herein. It should be noted that neural networks arefrequently combined with fuzzy logic and such a combination iscontemplated herein. The neural network is the first highly successfulof what will be a variety of pattern recognition techniques based ontraining. There is nothing that suggests that it is the only or even thebest technology. The characteristics of all of these technologies whichrender them applicable to this general diagnostic problem include theuse of time- of frequency-based input data and that they are trainable.In most cases, the pattern recognition technology learns from examplesof data characteristic of normal and abnormal component operation.

A diagram of one example of a neural network used for diagnosing anunbalanced tire, for example, based on the teachings of this inventionis shown in FIG. 2. The process can be programmed to periodically testfor an unbalanced tire. Since this need be done only infrequently, thesame processor can be used for many such diagnostic problems. When theparticular diagnostic test is run, data from the previously determinedrelevant sensor(s) is preprocessed and analyzed with the neural networkalgorithm. For the unbalanced tire, using the data from an accelerometerfor example, the digital acceleration values from the analog-to-digitalconverter in the accelerometer are entered into nodes 1 through n andthe neural network algorithm compares the pattern of values on nodes 1through n with patterns for which it has been trained as follows.

Each of the input nodes is usually connected to each of the second layernodes, h-1,h-2, . . . ,h-n, called the hidden layer, either electricallyas in the case of a neural computer, or through mathematical functionscontaining multiplying coefficients called weights. At each hidden layernode, a summation occurs of the values from each of the input layernodes, which have been operated on by functions containing the weights,to create a node value. Similarly, the hidden layer nodes are, in a likemanner, connected to the output layer node(s), which in this example isonly a single node 0 representing the decision to notify the driver,and/or a remote facility, of the unbalanced tire. During the trainingphase, an output node value of 1, for example, is assigned to indicatethat the driver should be notified and a value of 0 is assigned to notnotifying the driver.

In the example above, twenty input nodes were used, five hidden layernodes and one output layer node. In this example, only one sensor wasconsidered and accelerations from only one direction were used. If otherdata from other sensors such as accelerations from the vertical orlateral directions were also used, then the number of input layer nodeswould increase. Again, the theory for determining the complexity of aneural network for a particular application has been the subject of manytechnical papers and will not be presented in detail here. Determiningthe requisite complexity for the example presented here can beaccomplished by those skilled in the art of neural network design. Alsoone particular preferred type of neural network has been discussed. Manyother types exist as discussed in the above references and theinventions herein is not limited to the particular type discussed here.

Briefly, the neural network described above defines a method, using apattern recognition system, of sensing an unbalanced tire anddetermining whether to notify the driver, and/or a remote facility, andcomprises the steps of:

(a) obtaining an acceleration signal from an accelerometer mounted on avehicle;

(b) converting the acceleration signal into a digital time series;

(c) entering the digital time series data into the input nodes of theneural network;

(d) performing a mathematical operation on the data from each of theinput nodes and inputting the operated on data into a second series ofnodes wherein the operation performed on each of the input node dataprior to inputting the operated-on value to a second series node isdifferent from that operation performed on some other input node data(e.g., a different weight value can be used);

(e) combining the operated-on data from most or all of the input nodesinto each second series node to form a value at each second series node;

(f) performing a mathematical operation on each of the values on thesecond series of nodes and inputting this operated-on data into anoutput series of nodes wherein the operation performed on each of thesecond series node data prior to inputting the operated-on value to anoutput series node is different from that operation performed on someother second series node data;

(g) combining the operated-on data from most or all of the second seriesnodes into each output series node to form a value at each output seriesnode; and,

(h) notifying a driver if the value on one output series node is withina selected range signifying that a tire requires balancing.

This method can be generalized to a method of predicting that acomponent of a vehicle will fail comprising the steps of:

(a) sensing a signal emitted from the component;

(b) converting the sensed signal into a digital time series;

(c) entering the digital time series data into a pattern recognitionalgorithm;

(d) executing the pattern recognition algorithm to determine if thereexists within the digital time series data a pattern characteristic ofabnormal operation of the component; and

(e) notifying a driver and/or a remote facility if the abnormal patternis recognized.

The particular neural network described and illustrated above contains asingle series of hidden layer nodes. In some network designs, more thanone hidden layer is used, although only rarely will more than two suchlayers appear. There are of course many other variations of the neuralnetwork architecture illustrated above which appear in the referencedliterature. For the purposes herein, therefore, “neural network” can bedefined as a system wherein the data to be processed is separated intodiscrete values which are then operated on and combined in at least atwo stage process and where the operation performed on the data at eachstage is in general different for each discrete value and where theoperation performed is at least determined through a training process. Adifferent operation here is meant any difference in the way that theoutput of a neuron is treated before it is inputted into another neuronsuch as multiplying it by a different weight or constant.

The implementation of neural networks can take on at least two forms, analgorithm programmed on a digital microprocessor, FPGA, DSP or in aneural computer (including a cellular neural network or support vectormachine). In this regard, it is noted that neural computer chips are nowbecoming available.

In the example above, only a single component failure was discussedusing only a single sensor since the data from the single sensorcontains a pattern which the neural network was trained to recognize aseither normal operation of the component or abnormal operation of thecomponent. The diagnostic module 51 contains preprocessing and neuralnetwork algorithms for a number of component failures. The neuralnetwork algorithms are generally relatively simple, requiring only arelatively small number of lines of computer code. A single generalneural network program can be used for multiple pattern recognitioncases by specifying different coefficients for the various node inputs,one set for each application. Thus, adding different diagnostic checkshas only a small affect on the cost of the system. Also, the system canhave available to it all of the information available on the data bus.

During the training process, the pattern recognition program sorts outfrom the available vehicle data on the data bus or from other sources,those patterns that predict failure of a particular component. If morethan one sensor is used to sense the output from a component, such astwo spaced-apart microphones or acceleration sensors, then the locationof the component can sometimes be determined by triangulation based onthe phase difference, time of arrival and/or angle of arrival of thesignals to the different sensors. In this manner, a particular vibratingtire can be identified, for example. Since each tire on a vehicle doesnot always make the same number of revolutions in a given time period, atire can be identified by comparing the wheel sensor output with thevibration or other signal from the tire to identify the failing tire.The phase of the failing tire will change relative to the other tires,for example. This technique can also be used to associate a tirepressure monitor RF signal with a particular tire. An alternate methodfor tire identification makes use of an RFID tag or an RFID switch asdiscussed below.

In view of the foregoing, a method for diagnosing whether one or morecomponents of a vehicle are operating abnormally would entail in atraining stage, obtaining output from the sensors during normaloperation of the components, adjusting each component to induce abnormaloperation thereof and obtaining output from the sensors during theinduced abnormal operation, and determining which sensors provide dataabout abnormal operation of each component based on analysis of theoutput from the sensors during normal operation and during inducedabnormal operation of the component, e.g., differences between signalsoutput from the sensors during normal and abnormal operation. The outputfrom the sensors can be processed and pre-processed as described above.When obtaining output from the sensors during abnormal componentoperation, different abnormalities can be induced in the components, oneabnormality in one component at each time and/or multiple abnormalitiesin multiple components at one time.

During operation of the vehicle, output from the sensors is received anda determination is made whether any of the components are operatingabnormally by analyzing the output from those sensors which have beendetermined to provide data about abnormal operation of that component.This determination is used to alert a driver of the vehicle, a vehiclemanufacturer, a vehicle dealer or a vehicle repair facility about theabnormal operation of a component. As mentioned above, the determinationof whether any of the components are operating abnormally may involveconsidering output from only those sensors which have been determined toprovide data about abnormal operation of that component. This could be asubset of the sensors, although it is possible when using a neuralnetwork to input all of the sensor data with the neural network beingdesigned to disregard output from sensors which have no bearing on thedetermination of abnormal operation of the component operatingabnormally.

When a combination neural network 810 is used, its training can involvemultiple steps (see the description of FIGS. 92 and 93 in the parent'240 application).

In FIG. 3, a schematic of a vehicle with several components and severalsensors is shown in their approximate locations on a vehicle along witha total vehicle diagnostic system in accordance with the inventionutilizing a diagnostic module in accordance with the invention. A flowdiagram of information passing from the various sensors shown in FIG. 3onto the vehicle data bus, wireless communication system, wire harnessor a combination thereof, and thereby into the diagnostic device inaccordance with the invention is shown in FIG. 4 along with outputs to adisplay for notifying the driver and to the vehicle cellular phone, orother communication device, for notifying the dealer, vehiclemanufacturer or other entity concerned with the failure of a componentin the vehicle. If the vehicle is operating on a smart highway, forexample, the pending component failure information may also becommunicated to a highway control system and/or to other vehicles in thevicinity so that an orderly exiting of the vehicle from the smarthighway can be facilitated. FIG. 4 also contains the names of thesensors shown numbered in FIG. 3.

Note, where applicable in one or more of the inventions disclosedherein, any form of wireless communication is contemplated for intravehicle communications between various sensors and components includingamplitude modulation, frequency modulation, TDMA, CDMA, spread spectrum,ultra wideband and all variations. Similarly, all such methods are alsocontemplated for vehicle-to-vehicle or vehicle-to-infrastructurecommunication.

Sensor 1 is a crash sensor having an accelerometer (alternately one ormore dedicated accelerometers or IMUs 31 can be used), sensor 2 isrepresents one or more microphones, sensor 3 is a coolant thermometer,sensor 4 is an oil pressure sensor, sensor 5 is an oil level sensor,sensor 6 is an air flow meter, sensor 7 is a voltmeter, sensor 8 is aammeter, sensor 9 is a humidity sensor, sensor 10 is an engine knocksensor, sensor 11 is an oil turbidity sensor, sensor 12 is a throttleposition sensor, sensor 13 is a steering torque sensor, sensor 14 is awheel speed sensor, sensor 15 is a tachometer, sensor 16 is aspeedometer, sensor 17 is an oxygen sensor, sensor 18 is a pitch/rollsensor, sensor 19 is a clock, sensor 20 is an odometer, sensor 21 is apower steering pressure sensor, sensor 22 is a pollution sensor, sensor23 is a fuel gauge, sensor 24 is a cabin thermometer, sensor 25 is atransmission fluid level sensor, sensor 26 is a yaw sensor, sensor 27 isa coolant level sensor, sensor 28 is a transmission fluid turbiditysensor, sensor 29 is brake pressure sensor and sensor 30 is a coolantpressure sensor. Other possible sensors include a temperaturetransducer, a pressure transducer, a liquid level sensor, a flow meter,a position sensor, a velocity sensor, a RPM sensor, a chemical sensorand an angle sensor, angular rate sensor or gyroscope.

If a distributed group of acceleration sensors or accelerometers areused to permit a determination of the location of a vibration source,the same group can, in some cases, also be used to measure the pitch,yaw and/or roll of the vehicle eliminating the need for dedicatedangular rate sensors. In addition, as mentioned above, such a suite ofsensors can also be used to determine the location and severity of avehicle crash and additionally to determine that the vehicle is on theverge of rolling over. Thus, the same suite of accelerometers optimallyperforms a variety of functions including inertial navigation, crashsensing, vehicle diagnostics, roll-over sensing etc.

Consider now some examples. The following is a partial list of potentialcomponent failures and the sensors from the list in FIG. 4 that mightprovide information to predict the failure of the component: Out ofbalance tires 1, 13, 14, 15, 20, 21 Front end out of alignment 1, 13,21, 26 Tune up required 1, 3, 10, 12, 15, 17, 20, 22 Oil change needed3, 4, 5, 11 Motor failure 1, 2, 3, 4, 5, 6, 10, 12, 15, 17, 22 Low tirepressure 1, 13, 14, 15, 20, 21 Front end looseness 1, 13, 16, 21, 26Cooling system failure 3, 15, 24, 27, 30 Alternator problems 1, 2, 7, 8,15, 19, 20 Transmission problems 1, 3, 12, 15, 16, 20, 25, 28Differential problems 1, 12, 14 Brakes 1, 2, 14, 18, 20, 26, 29Catalytic converter and muffler 1, 2, 12, 15, 22 Ignition 1, 2, 7, 8, 9,10, 12, 17, 23 Tire wear 1, 13, 14, 15, 18, 20, 21, 26 Fuel leakage 20,23 Fan belt slippage 1, 2, 3, 7, 8, 12, 15, 19, 20 Alternatordeterioration 1, 2, 7, 8, 15, 19 Coolant pump failure 1, 2, 3, 24, 27,30 Coolant hose failure 1, 2, 3, 27, 30 Starter failure 1, 2, 7, 8, 9,12, 15 Dirty air filter 2, 3, 6, 11, 12, 17, 22

Several interesting facts can be deduced from a review of the abovelist. First, all of the failure modes listed can be at least partiallysensed by multiple sensors. In many cases, some of the sensors merelyadd information to aid in the interpretation of signals received fromother sensors. In today's automobile, there are few if any cases wheremultiple sensors are used to diagnose or predict a problem. In fact,there is virtually no failure prediction (prognostics) undertaken atall. Second, many of the failure modes listed require information frommore than one sensor. Third, information for many of the failure modeslisted cannot be obtained by observing one data point in time as is nowdone by most vehicle sensors. Usually an analysis of the variation in aparameter as a function of time is necessary. In fact, the associationof data with time to create a temporal pattern for use in diagnosingcomponent failures in automobile is believed to be unique to theinventions herein as is the combination of several such temporalpatterns. Fourth, the vibration measuring capability of the airbag crashsensor, or other accelerometer or IMU, is useful for most of the casesdiscussed above yet there is no such current use of accelerometers. Theairbag crash sensor is used only to detect crashes of the vehicle.Fifth, the second most used sensor in the above list, a microphone, doesnot currently appear on any automobiles, yet sound is the signal mostoften used by vehicle operators and mechanics to diagnose vehicleproblems. Another sensor that is listed above which also does notcurrently appear on automobiles is a pollution sensor. This is typicallya chemical sensor mounted in the exhaust system for detecting emissionsfrom the vehicle. It is expected that this and other chemical andbiological sensors will be used more in the future. Such a sensor can beused to monitor the intake of air from outside the vehicle to permitsuch a flow to be cut off when it is polluted. Similarly, if theinterior air is polluted, the exchange with the outside air can beinitiated.

In addition, from the foregoing depiction of different sensors whichreceive signals from a plurality of components, it is possible for asingle sensor to receive and output signals from a plurality ofcomponents which are then analyzed by the processor to determine if anyone of the components for which the received signals were obtained bythat sensor is operating in an abnormal state. Likewise, it is alsopossible to provide for a plurality of sensors each receiving adifferent signal related to a specific component which are then analyzedby the processor to determine if that component is operating in anabnormal state. Neural networks can simultaneously analyze data frommultiple sensors of the same type or different types (a form of sensorfusion).

As can be appreciated from the above discussion, an invention describedherein brings several new improvements to vehicles including, but notlimited to, the use of pattern recognition technologies to diagnosepotential vehicle component failures, the use of trainable systemsthereby eliminating the need of complex and extensive programming, thesimultaneous use of multiple sensors to monitor a particular component,the use of a single sensor to monitor the operation of many vehiclecomponents, the monitoring of vehicle components which have no dedicatedsensors, and the notification of both the driver and possibly an outsideentity of a potential component failure prior to failure so that theexpected failure can be averted and vehicle breakdowns substantiallyeliminated. Additionally, improvements to the vehicle stability, crashavoidance, crash anticipation and occupant protection are available.

To implement a component diagnostic system for diagnosing the componentutilizing a plurality of sensors not directly associated with thecomponent, i.e., independent of the component, a series of tests areconducted. For each test, the signals received from the sensors areinput into a pattern recognition training algorithm with an indicationof whether the component is operating normally or abnormally (thecomponent being intentionally altered to provide for abnormaloperation). The data from the test are used to generate the patternrecognition algorithm, e.g., neural network, so that in use, the datafrom the sensors is input into the algorithm and the algorithm providesan indication of abnormal or normal operation of the component. Also, toprovide a more versatile diagnostic module for use in conjunction withdiagnosing abnormal operation of multiple components, tests may beconducted in which each component is operated abnormally while the othercomponents are operating normally, as well as tests in which two or morecomponents are operating abnormally. In this manner, the diagnosticmodule may be able to determine based on one set of signals from thesensors during use that either a single component or multiple componentsare operating abnormally. Additionally, if a failure occurs which wasnot forecasted, provision can be made to record the output of some orall of the vehicle data and later make it available to the vehiclemanufacturer for inclusion into the pattern recognition trainingdatabase. Also, it is not necessary that a neural network system that ison a vehicle be a static system and some amount of learning can, in somecases, be permitted. Additionally, as the vehicle manufacturer updatesthe neural networks, the newer version can be downloaded to particularvehicles either when the vehicle is at a dealership or wirelessly via acellular network or by satellite.

Furthermore, the pattern recognition algorithm may be trained based onpatterns within the signals from the sensors. Thus, by means of a singlesensor, it would be possible to determine whether one or more componentsare operating abnormally. To obtain such a pattern recognitionalgorithm, tests are conducted using a single sensor, such as amicrophone, and causing abnormal operation of one or more components,each component operating abnormally while the other components operatenormally and multiple components operating abnormally. In this manner,in use, the pattern recognition algorithm may analyze a signal from asingle sensor and determine abnormal operation of one or morecomponents. Note that in some cases, simulations can be used toanalytically generate the relevant data.

The discussion above has centered mainly on the blind training of apattern recognition system, such as a neural network, so that faults canbe discovered and failures forecast before they happen. Naturally, thediagnostic algorithms do not have to start out being totally dumb and infact, the physics or structure of the systems being monitored can beappropriately used to help structure or derive the diagnosticalgorithms. Such a system is described in a recent article “ImmobotsTake Control”, MIT Technology Review December, 2002. Also, of course, itis contemplated that once a potential failure has been diagnosed, thediagnostic system can in some cases act to change the operation ofvarious systems in the vehicle to prolong the time of a failingcomponent before the failure or in some rare cases, the situationcausing the failure might be corrected. An example of the first case iswhere the alternator is failing and various systems or components can beturned off to conserve battery power and an example of the second caseis rollover of a vehicle may be preventable through the properapplication of steering torque and wheel braking force. Such algorithmscan be based on pattern recognition or on models, as described in theImmobot article referenced above, or a combination thereof and all suchsystems are contemplated by the invention described herein.

1.3 SAW and Other Wireless Sensors

Many sensors are now in vehicles and many more will be installed invehicles. The following disclosure is primarily concerned with wirelesssensors which can be based on MEMS, SAW and/or RFID technologies.Vehicle sensors include tire pressure, temperature and accelerationmonitoring sensors; weight or load measuring sensors; switches; vehicletemperature, acceleration, angular position, angular rate, angularacceleration sensors; proximity; rollover; occupant presence; humidity;presence of fluids or gases; strain; road condition and friction,chemical sensors and other similar sensors providing information to avehicle system, vehicle operator or external site. The sensors canprovide information about the vehicle and/or its interior or exteriorenvironment, about individual components, systems, vehicle occupants,subsystems, and/or about the roadway, ambient atmosphere, travelconditions and external objects.

For wireless sensors, one or more interrogators can be used each havingone or more antennas that transmit energy at radio frequency, or otherelectromagnetic frequencies, to the sensors and receive modulatedfrequency signals from the sensors containing sensor and/oridentification information. One interrogator can be used for sensingmultiple switches or other devices. For example, an interrogator maytransmit a chirp form of energy at 905 MHz to 925 MHz to a variety ofsensors located within and/or in the vicinity of the vehicle. Thesesensors may be of the RFID electronic type and/or of the surfaceacoustic wave (SAW) type or a combination thereof. In the electronictype, information can be returned immediately to the interrogator in theform of a modulated backscatter RF signal. In the case of SAW devices,the information can be returned after a delay. RFID tags may alsoexhibit a delay due to the charging of the energy storage device.Naturally, one sensor can respond in both the electronic (either RFID orbackscatter) and SAW delayed modes.

When multiple sensors are interrogated using the same technology, thereturned signals from the various sensors can be time, code, space orfrequency multiplexed. For example, for the case of the SAW technology,each sensor can be provided with a different delay or a different code.Alternately, each sensor can be designed to respond only to a singlefrequency or several frequencies. The radio frequency can be amplitude,code or frequency modulated. Space multiplexing can be achieved throughthe use of two or more antennas and correlating the received signals toisolate signals based on direction.

In many cases, the sensors will respond with an identification signalfollowed by or preceded by information relating to the sensed value,state and/or property. In the case of a SAW-based or RFID-based switch,for example, the returned signal may indicate that the switch is eitheron or off or, in some cases, an intermediate state can be providedsignifying that a light should be dimmed, rather than or on or off, forexample. Alternately or additionally, an RFID based switch can beassociated with a sensor and turned on or off based on an identificationcode or a frequency sent from the interrogator permitting a particularsensor or class of sensors to be selected.

SAW devices have been used for sensing many parameters including devicesfor chemical and biological sensing and materials characterization inboth the gas and liquid phase. They also are used for measuringpressure, strain, temperature, acceleration, angular rate and otherphysical states of the environment.

Economies are achieved by using a single interrogator or even a smallnumber of interrogators to interrogate many types of devices. Forexample, a single interrogator may monitor tire pressure andtemperature, the weight of an occupying item of the seat, the positionof the seat and seatback, as well as a variety of switches controllingwindows, door locks, seat position, etc. in a vehicle. Such aninterrogator may use one or multiple antennas and when multiple antennasare used, may switch between the antennas depending on what is beingmonitored.

Similarly, the same or a different interrogator can be used to monitorvarious components of the vehicle's safety system including occupantposition sensors, vehicle acceleration sensors, vehicle angularposition, velocity and acceleration sensors, related to both frontal,side or rear impacts as well as rollover conditions. The interrogatorcould also be used in conjunction with other detection devices such asweight sensors, temperature sensors, accelerometers which are associatedwith various systems in the vehicle to enable such systems to becontrolled or affected based on the measured state.

Some specific examples of the use of interrogators and responsivedevices will now be described.

The antennas used for interrogating the vehicle tire pressuretransducers can be located outside of the vehicle passenger compartment.For many other transducers to be sensed the antennas can be located atvarious positions within passenger compartment. At least one inventionherein contemplates, therefore, a series of different antenna systems,which can be electronically switched by the interrogator circuitry.Alternately, in some cases, all of the antennas can be left connectedand total transmitted power increased.

There are several applications for weight or load measuring devices in avehicle including the vehicle suspension system and seat weight sensorsfor use with automobile safety systems. As described in U.S. Pat. No.4,096,740, U.S. Pat. No. 4,623,813, U.S. Pat. No. 5,585,571, U.S. Pat.No. 5,663,531, U.S. Pat. No. 5,821,425 and U.S. Pat. No. 5,910,647 andInternational Publication No. WO 00/65320(A1), SAW devices areappropriate candidates for such weight measurement systems, although insome cases RFID systems can also be used with an associated sensor suchas a strain gage. In this case, the surface acoustic wave on the lithiumniobate, or other piezoelectric material, is modified in delay time,resonant frequency, amplitude and/or phase based on strain of the memberupon which the SAW device is mounted. For example, the conventional boltthat is typically used to connect the passenger seat to the seatadjustment slide mechanism can be replaced with a stud which is threadedon both ends. A SAW or other strain device can be mounted to the centerunthreaded section of the stud and the stud can be attached to both theseat and the slide mechanism using appropriate threaded nuts. Based onthe particular geometry of the SAW device used, the stud can result inas little as a 3 mm upward displacement of the seat compared to a normalbolt mounting system. No wires are required to attach the SAW device tothe stud other than for an antenna.

In use, the interrogator transmits a radio frequency pulse at, forexample, 925 MHz that excites antenna on the SAW strain measuringsystem. After a delay caused by the time required for the wave to travelthe length of the SAW device, a modified wave is re-transmitted to theinterrogator providing an indication of the strain of the stud with theweight of an object occupying the seat corresponding to the strain. Fora seat that is normally bolted to the slide mechanism with four bolts,at least four SAW strain sensors could be used. Since the individual SAWdevices are very small, multiple devices can be placed on a stud toprovide multiple redundant measurements, or permit bending and twistingstrains to be determined, and/or to permit the stud to be arbitrarilylocated with at least one SAW device always within direct view of theinterrogator antenna. In some cases, the bolt or stud will be made onnon-conductive material to limit the blockage of the RF signal. In othercases, it will be insulated from the slide (mechanism) and used as anantenna.

If two longitudinally spaced apart antennas are used to receive the SAWor RFID transmissions from the seat weight sensors, one antenna in frontof the seat and the other behind the seat, then the position of the seatcan be determined eliminating the need for current seat positionsensors. A similar system can be used for other seat and seatbackposition measurements.

For strain gage weight sensing, the frequency of interrogation can beconsiderably higher than that of the tire monitor, for example. However,if the seat is unoccupied, then the frequency of interrogation can besubstantially reduced. For an occupied seat, information as to theidentity and/or category and position of an occupying item of the seatcan be obtained through the multiple weight sensors described. For thisreason, and due to the fact that during the pre-crash event, theposition of an occupying item of the seat may be changing rapidly,interrogations as frequently as once every 10 milliseconds or faster canbe desirable. This would also enable a distribution of the weight beingapplied to the seat to be obtained which provides an estimation of thecenter of pressure and thus the position of the object occupying theseat. Using pattern recognition technology, e.g., a trained neuralnetwork, sensor fusion, fuzzy logic, etc., an identification of theobject can be ascertained based on the determined weight and/ordetermined weight distribution.

There are many other methods by which SAW devices can be used todetermine the weight and/or weight distribution of an occupying itemother than the method described above and all such uses of SAW strainsensors for determining the weight and weight distribution of anoccupant are contemplated. For example, SAW devices with appropriatestraps can be used to measure the deflection of the seat cushion top orbottom caused by an occupying item, or if placed on the seat belts, theload on the belts can determined wirelessly and powerlessly. Geometriessimilar to those disclosed in U.S. Pat. No. 6,242,701 (which disclosesmultiple strain gage geometries) using SAW strain-measuring devices canalso be constructed, e.g., any of the multiple strain gage geometriesshown therein.

Generally there is an RFID implementation that corresponds to each SAWimplementation. Therefore, where SAW is used herein the equivalent RFIDdesign will also be meant where appropriate.

Although a preferred method for using the invention is to interrogateeach of the SAW devices using wireless mechanisms, in some cases, it maybe desirable to supply power to and/or obtain information from one ormore of the SAW devices using wires. As such, the wires would be anoptional feature.

One advantage of the weight sensors of this invention along with thegeometries disclosed in the '701 patent and herein below, is that inaddition to the axial stress in the seat support, the bending moments inthe structure can be readily determined. For example, if a seat issupported by four “legs”, it is possible to determine the state ofstress, assuming that axial twisting can be ignored, using four straingages on each leg support for a total of 16 such gages. If the seat issupported by three legs, then this can be reduced to 12 gages.Naturally, a three-legged support is preferable to four since with fourlegs, the seat support is over-determined which severely complicates thedetermination of the stress caused by an object on the seat. Even withthree supports, stresses can be introduced depending on the nature ofthe support at the seat rails or other floor-mounted supportingstructure. If simple supports are used that do not introduce bendingmoments into the structure, then the number of gages per seat can bereduced to three, provided a good model of the seat structure isavailable. Unfortunately, this is usually not the case and most seatshave four supports and the attachments to the vehicle not only introducebending moments into the structure but these moments vary from oneposition to another and with temperature. The SAW strain gages of thisinvention lend themselves to the placement of multiple gages onto eachsupport as needed to approximately determine the state of stress andthus the weight of the occupant depending on the particular vehicleapplication. Furthermore, the wireless nature of these gages greatlysimplifies the placement of such gages at those locations that are mostappropriate.

An additional point should be mentioned. In many cases, thedetermination of the weight of an occupant from the static strain gagereadings yields inaccurate results due to the indeterminate stress statein the support structure. However, the dynamic stresses to a first orderare independent of the residual stress state. Thus, the change in stressthat occurs as a vehicle travels down a roadway caused by dips in theroadway can provide an accurate measurement of the weight of an objectin a seat. This is especially true if an accelerometer is used tomeasure the vertical excitation provided to the seat.

Some vehicle models provide load leveling and ride control functionsthat depend on the magnitude and distribution of load carried by thevehicle suspension. Frequently, wire strain gage technology is used forthese functions. That is, the wire strain gages are used to sense theload and/or load distribution of the vehicle on the vehicle suspensionsystem. Such strain gages can be advantageously replaced with straingages based on SAW technology with the significant advantages in termsof cost, wireless monitoring, dynamic range, and signal level. Inaddition, SAW strain gage systems can be more accurate than wire straingage systems.

A strain detector in accordance with this invention can convertmechanical strain to variations in electrical signal frequency with alarge dynamic range and high accuracy even for very small displacements.The frequency variation is produced through use of a surface acousticwave (SAW) delay line as the frequency control element of an oscillator.A SAW delay line comprises a transducer deposited on a piezoelectricmaterial such as quartz or lithium niobate which is arranged so as to bedeformed by strain in the member which is to be monitored. Deformationof the piezoelectric substrate changes the frequency controlcharacteristics of the surface acoustic wave delay line, therebychanging the frequency of the oscillator. Consequently, the oscillatorfrequency change is a measure of the strain in the member beingmonitored and thus the weight applied to the seat. A SAW straintransducer can be more accurate than a conventional resistive straingage.

Other applications of weight measuring systems for an automobile includemeasuring the weight of the fuel tank or other containers of fluid todetermine the quantity of fluid contained therein as described below.

One problem with SAW devices is that if they are designed to operate atthe GHz frequency, the feature sizes become exceeding small and thedevices are difficult to manufacture, although techniques are nowavailable for making SAW devices in the tens of GHz range. On the otherhand, if the frequencies are considerably lower, for example, in thetens of megahertz range, then the antenna sizes become excessive. It isalso more difficult to obtain antenna gain at the lower frequencies.This is also related to antenna size. One method of solving this problemis to transmit an interrogation signal in the high GHz range which ismodulated at the hundred MHz range. At the SAW transducer, thetransducer is tuned to the modulated frequency. Using a nonlinear devicesuch as a Shocky diode, the modified signal can be mixed with theincoming high frequency signal and re-transmitted through the sameantenna. For this case, the interrogator can continuously broadcast thecarrier frequency.

Devices based on RFID or SAW technology can be used as switches in avehicle as described in U.S. Pat. No. 6,078,252, U.S. Pat. No. 6,144,288and U.S. Pat. No. 6,748,797. There are many ways that this can beaccomplished. A switch can be used to connect an antenna to either anRFID electronic device or to a SAW device. This of course requirescontacts to be closed by the switch activation. An alternate approach isto use pressure from an occupant's finger, for example, to alter theproperties of the acoustic wave on the SAW material much as in a SAWtouch screen. The properties that can be modified include the amplitudeof the acoustic wave, and its phase, and/or the time delay or anexternal impedance connected to one of the SAW reflectors as disclosedin U.S. Pat. No. 6,084,503. In this implementation, the SAW transducercan contain two sections, one which is modified by the occupant and theother which serves as a reference. A combined signal is sent to theinterrogator that decodes the signal to determine that the switch hasbeen activated. By any of these technologies, switches can bearbitrarily placed within the interior of an automobile, for example,without the need for wires. Since wires and connectors are the cause ofmost warranty repairs in an automobile, not only is the cost of switchessubstantially reduced but also the reliability of the vehicle electricalsystem is substantially improved.

The interrogation of switches can take place with moderate frequencysuch as once every 100 milliseconds. Either through the use of differentfrequencies or different delays, a large number of switches can be time,code, space and/or frequency multiplexed to permit separation of thesignals obtained by the interrogator. Alternately, an RF activatedswitch on some or all of the sensors can be used as discussed below.

Another approach is to attach a variable impedance device across one ofthe reflectors on the SAW device. The impedance can therefore be used todetermine the relative reflection from the reflector compared to otherreflectors on the SAW device. In this manner, the magnitude as well asthe presence of a force exerted by an occupant's finger, for example,can be used to provide a rate sensitivity to the desired function. In analternate design, as shown U.S. Pat. No. 6,144,288, the switch is usedto connect the antenna to the SAW device. Of course, in this case, theinterrogator will not get a return from the SAW switch unless it isdepressed.

Temperature measurement is another field in which SAW technology can beapplied and the invention encompasses several embodiments of SAWtemperature sensors.

U.S. Pat. No. 4,249,418 is one of many examples of prior art SAWtemperature sensors. Temperature sensors are commonly used withinvehicles and many more applications might exist if a low cost wirelesstemperature sensor is available such as disclosed herein. The SAWtechnology can be used for such temperature sensing tasks. These tasksinclude measuring the vehicle coolant temperature, air temperaturewithin passenger compartment at multiple locations, seat temperature foruse in conjunction with seat warming and cooling systems, outsidetemperatures and perhaps tire surface temperatures to provide earlywarning to operators of road freezing conditions. One example, is toprovide air temperature sensors in the passenger compartment in thevicinity of ultrasonic transducers used in occupant sensing systems asdescribed in U.S. Pat. No. 5,943,295, since the speed of sound in theair varies by approximately 20% from −40° C. to 85° C. Currentultrasonic occupant sensor systems do not measure or compensate for thischange in the speed of sound with the effect of reducing the accuracy ofthe systems at the temperature extremes. Through the judicious placementof SAW temperature sensors in the vehicle, the passenger compartment airtemperature can be accurately estimated and the information providedwirelessly to the ultrasonic occupant sensor system thereby permittingcorrections to be made for the change in the speed of sound.

Since the road can be either a source or a sink of thermal energy,strategically placed sensors that measure the surface temperature of atire can also be used to provide an estimate of road temperature.

Acceleration sensing is another field in which SAW technology can beapplied and the invention encompasses several embodiments of SAWaccelerometers.

U.S. Pat. No. 4,199,990, U.S. Pat. No. 4,306,456 and U.S. Pat. No.4,549,436 are examples of prior art SAW accelerometers. Most airbagcrash sensors for determining whether the vehicle is experiencing afrontal or side impact currently use micromachined accelerometers. Theseaccelerometers are usually based on the deflection of a mass which issensed using either capacitive or piezoresistive technologies. SAWtechnology has previously not been used as a vehicle accelerometer orfor vehicle crash sensing. Due to the importance of this function, atleast one interrogator could be dedicated to this critical function.Acceleration signals from the crash sensors should be reported at leastpreferably every 100 microseconds. In this case, the dedicatedinterrogator would send an interrogation pulse to all crash sensoraccelerometers every 100 microseconds and receive staggered accelerationresponses from each of the SAW accelerometers wirelessly. Thistechnology permits the placement of multiple low-cost accelerometers atideal locations for crash sensing including inside the vehicle sidedoors, in the passenger compartment and in the frontal crush zone.Additionally, crash sensors can now be located in the rear of thevehicle in the crush zone to sense rear impacts. Since the accelerationdata is transmitted wirelessly, concern about the detachment or cuttingof wires from the sensors disappears. One of the main concerns, forexample, of placing crash sensors in the vehicle doors where they mostappropriately can sense vehicle side impacts, is the fear that an impactinto the A-pillar of the automobile would sever the wires from thedoor-mounted crash sensor before the crash was sensed. This problemdisappears with the current wireless technology of this invention. Iftwo accelerometers are placed at some distance from each other, the rollacceleration of the vehicle can be determined and thus the tendency ofthe vehicle to rollover can be predicted in time to automatically takecorrective action and/or deploy a curtain airbag or other airbag(s).Other types of sensors such as crash sensors based on pressuremeasurements, such as supplied by Siemens, can also now be wireless.

Although the sensitivity of measurement is considerably greater thanthat obtained with conventional piezo-electric or micromachinedaccelerometers, the frequency deviation of SAW devices remains low (inabsolute value). Accordingly, the frequency drift of thermal originshould be made as low as possible by selecting a suitable cut of thepiezoelectric material. The resulting accuracy is impressive aspresented in U.S. Pat. No. 4,549,436, which discloses an angularaccelerometer with a dynamic a range of 1 million, temperaturecoefficient of 0.005%/deg F, an accuracy of 1 microradian/sec², a powerconsumption of 1 milliwatt, a drift of 0.01% per year, a volume of 1cc/axis and a frequency response of 0 to 1000 Hz. The subject matter ofthe '436 patent is hereby included in the invention to constitute a partof the invention. A similar design can be used for acceleration sensing.

In a similar manner as the polymer-coated SAW device is used to measurepressure, a device wherein a seismic mass is attached to a SAW devicethrough a polymer interface can be made to sense acceleration. Thisgeometry has a particular advantage for sensing accelerations below 1 G,which has proved to be very difficult for conventional micro-machinedaccelerometers due to their inability to both measure low accelerationsand withstand high acceleration shocks.

Gyroscopes are another field in which SAW technology can be applied andthe inventions herein encompass several embodiments of SAW gyroscopes.

SAW technology is particularly applicable for gyroscopes as described inInternational Publication No. WO 00/79217A2. Output of such gyroscopescan be determined with an interrogator that is also used for the crashsensor accelerometers, or a dedicated interrogator can be used.Gyroscopes having an accuracy of approximately 1 degree per second havemany applications in a vehicle including skid control and other dynamicstability functions. Additionally, gyroscopes of similar accuracy can beused to sense impending vehicle rollover situations in time to takecorrective action.

It is believed that SAW gyroscopes of the type described in WO00/79217A2 have the capability of achieving accuracies approaching about3 degrees per hour. This high accuracy permits use of such gyroscopes inan inertial measuring unit (IMU) that can be used with accurate vehiclenavigation systems and autonomous vehicle control based on differentialGPS corrections. Such a system is described in U.S. Pat. No. 6,370,475.An alternate preferred technology for an IMU is described in U.S. Pat.No. 4,711,125 to Morrison discussed below. Such navigation systemsdepend on the availability of four or more GPS satellites and anaccurate differential correction signal such as provided by the OmniStarCorporation, NASA or through the National Differential GPS system nowbeing deployed. The availability of these signals degrades in urbancanyon environments, in tunnels and on highways when the vehicle is inthe vicinity of large trucks. For this application, an IMU system shouldbe able to accurately control the vehicle for perhaps 15 seconds andpreferably for up to five minutes. IMUs based on SAW technology, thetechnology of U.S. Pat. No. 4,549,436 discussed above or of the U.S.Pat. No. 4,711,125 are the best-known devices capable of providingsufficient accuracies for this application at a reasonable cost. Otheraccurate gyroscope technologies such as fiber optic systems are moreaccurate but can be cost-prohibitive, although recent analysis by thecurrent assignee indicates that such gyroscopes can eventually be madecost-competitive. In high volume production, an IMU of the requiredaccuracy based on SAW technology is estimated to cost less than about$100. A cost competing technology is that disclosed in U.S. Pat. No.4,711,125 which does not use SAW technology.

What follows is a discussion of the Morrison Cube of U.S. Pat. No.4,711,125 known as the QUBIK™. Let us review the typical problems thatare encountered with sensors that try to measure multiple physicalquantities at the same time and how the QUBIK solves these problems.These problems were provided by an IMU expert unfamiliar with the QUBIKand the responses are provided by Morrison.

1. Problem: Errors of measurement of the linear accelerations andangular speed are mutually correlated. Even if every one of the errors,taken separately, does not accumulate with integration (the inertialsystem's algorithm does that), the cross-coupled multiplication (such asone during re-projecting the linear accelerations from one coordinatesystem to another) will have these errors detected and will make them asystematic error similar to a sensor's bias.

Solution: The QUBIK IMU is calibrated and compensated for any cross axissensitivity. For example: if one of the angular accelerometer channelshas a sensitivity to any of the three of linear accelerations, then thelinear accelerations are buffered and scaled down and summed with thebuffered angular accelerometer output to cancel out all linearacceleration sensitivity on all three angular accelerometer channels.This is important to detect pure angular rate signals. This is a verycommon practice throughout the U.S. aerospace industry to makenavigation grade IMU's. Even when individual gyroscopes andaccelerometers are used in navigation, they have their outputs scaledand summed together to cancel out these cross axis errors. Note thatcompetitive MEMS products have orders of magnitude higher cross axissensitivities when compared to navigation grade sensors and they willundoubtedly have to use this practice to improve performance. MEMSangular rate sensors are advertised in degrees per second and navigationangular rate sensors are advertised in degrees per hour. MEMS angularrate sensors have high linear acceleration errors that must becompensated for at the IMU level.

2. Problem: The gyroscope and accelerometer channels require settings tobe made that contradict one another physically. For example, a gapbetween the cube and the housing for the capacitive sensors (thatmeasure the displacements of the cube) is not to exceed 50 to 100microns. On the other hand, the gyroscope channels require, in order toenhance a Coriolis effect used to measure the angular speed, that theamplitude and the linear speed of vibrations are as big as possible. Todo this, the gap and the frequency of oscillations should be increased.A greater frequency of oscillations in the nearly resonant mode requiresthe stiffness of the electromagnetic suspension to be increased, too,which leads to a worse measurement of the linear accelerations becausethe latter require that the rigidity of the suspension be minimal whenthere is a closed feedback.

Solution: The capacitive gap all around the levitated inner cube of theQUBIK is nominally 0.010 inches. The variable capacitance plates areexcited by a 1.5 MHz 25 volt peak to peak signal. The signal coming outis so strong (five volts) that there is no preamp required. Diodedetectors are mounted directly above the capacitive plates. There is noperformance change in the linear accelerometer channels when the angularaccelerometer channels are being dithered or rotated back and forthabout an axis. This was discovered by having a ground plane around theelectromagnets that eliminated transformer coupling. Dithering ordriving the angular accelerometer which rotates the inner cube proofmass is a gyroscopic displacement and not a linear displacement and hasno effect on the linear channels. Another very important point to makeis the servo loops measure the force required to keep the inner cube atits null and the servo loops are integrated to prevent anydisplacements. The linear accelerometer servo loops are not beingexercised to dither the inner cube. The angular accelerometer servo loopis being exercised. The linear and angular channels have their ownseparate set of capacitance detectors and electromagnets. Driving theangular channels has no effect on the linear ones.

The rigidity of an integrated closed loop servo is infinite at DC androlls off at higher frequencies. The QUBIK IMU measures the force beingapplied to the inner cube and not the displacement to measure angularrate. There is a force generated on the inner cube when it is beingrotated and the servo will not allow any displacement by applying equaland opposite forces on the inner cube to keep it at null. The servoreadout is a direct measurement of the gyroscopic forces on the innercube and not the displacement.

The servo gain is so high at the null position that one will not see thenull displacement but will see a current level equivalent to the forceon the cube. This is why integrated closed loop servos are so good. Theymeasure the force required to keep the inner cube at null and not thedisplacement. The angular accelerometer channel that is being ditheredwill have a noticeable displacement at its null. The sensor does nothave to be driven at its resonance. Driving the angular accelerometer atresonance will run the risk of over-driving the inner cube to the pointwhere it will bottom out and bang around inside its cavity. There is anactive gain control circuit to keep the alternating momentum constant.

Note that competitive MEMS based sensors are open loop and allowdisplacements which increase cross axis errors. MEMS sensors must havedisplacements to work and do not measure the Coriolis force, theymeasure displacement which results in huge cross axis sensitivityissues.

3. Problem: As the electromagnetic suspension is used, the sensor isgoing to be sensitive to external constant and variable (alternating)fields. Its errors will vary with its position, for example, withrespect to the Earth's magnetic field or other magnetic sources.

Solution: The earths magnetic field varies from −0.0 to +0.3 gauss andthe magnets have gauss levels over 10,000. The earth field can beshielded if necessary.

4. Problem: The QUBIT sensing element is relatively heavy so the sensoris likely to be sensitive to angular accelerations and impacts. Also,the temperature of the environment can affect the micron-sized gaps,magnetic fields of the permanent magnets, the resistance of theinductance coils etc., which will eventually increase the sensor errors.

Solution: The inner cube has a gap of 0.010 inches and does not changesignificantly over temperature.

The resistance of the coils is not a factor in the active closed loopservo. Anybody who make this statement does not know what they aretalking about. There is a stable one PPM/C current readout resistor inseries with the coil that measures the current passing through the coilwhich eliminates the temperature sensitivity of the coil resistance.

Permanent magnets have already proven themselves to be very stable overtemperature when used in active servo loops used in navigationgyroscopes and accelerometers.

Note that the sensitivity that the QUBIK IMU has achieved 0.01 degreesper hour.

5. Problem: High Cost. To produce the QUBIK, one may need to maintainmicron-sized gaps and highly clean surfaces for capacitive sensors; thedevices must be assembled in a dust-free room, and the device itselfmust be hermetic (otherwise dust or moisture will put the capacitivesensor and the electromagnetic suspension out of operation), thepermanent magnets must have a very stable performance because they'regoing to work in a feedback circuit, and so on. In our opinion, allthese issues make the technology overly complex and expensive, so anadditional metrological control will be required and no full automationcan be ever done.

Solution: The sensor does not have micron size gaps and does not need tobe hermetic unless the sensor is submerged in water! Most of the QUBIKIMU sensor is a cut out PCB's that can certainly be automated. The PCBdesign can keep dust out and does not need to be hermetic. Humidity isnot a problem unless the sensor is submerged in water. The permanentmagnets achieve parts per million stability at a cost of $0.05 each fora per system cost of under one dollar. There are may navigation gradegyroscopes and accelerometers that use permanent magnets.

Competitive MEMS sensors can of course have process contaminationproblems. To my knowledge, there are no MEMS angular rate sensors thatdo not require human labor and/or calibration. The QUBIK IMU can insteaduse programmable potentiometers at calibration instead of human labor.

Once an IMU of the accuracy described above is available in the vehicle,this same device can be used to provide significant improvements tovehicle stability control and rollover prediction systems.

Keyless entry systems are another field in which SAW technology can beapplied and the invention encompasses several embodiments of accesscontrol systems using SAW devices.

A common use of SAW or RFID technology is for access control tobuildings however, the range of electronic unpowered RFID technology isusually limited to one meter or less. In contrast, the SAW technology,when powered or boosted, can permit sensing up to about 30 meters. As akeyless entry system, an automobile can be configured such that thedoors unlock as the holder of a card containing the SAW ID systemapproaches the vehicle and similarly, the vehicle doors can beautomatically locked when the occupant with the card travels beyond acertain distance from the vehicle. When the occupant enters the vehicle,the doors can again automatically lock either through logic or through acurrent system wherein doors automatically lock when the vehicle isplaced in gear. An occupant with such a card would also not need to havean ignition key. The vehicle would recognize that the SAW-based card wasinside vehicle and then permit the vehicle to be started by issuing anoral command if a voice recognition system is present or by depressing abutton, for example, without the need for an ignition key.

SAW sensors operating in the wireless mode can also be used to sense forice on the windshield or other exterior surfaces of the vehicle,condensation on the inside of the windshield or other interior surfaces,rain sensing, heat-load sensing and many other automotive sensingfunctions. They can also be used to sense outside environmentalproperties and states including temperature, humidity, etc.

SAW sensors can be economically used to measure the temperature andhumidity at numerous places both inside and outside of a vehicle. Whenused to measure humidity inside the vehicle, a source of water vapor canbe activated to increase the humidity when desirable and the airconditioning system can be activated to reduce the humidity whennecessary or desirable. Temperature and humidity measurements outside ofthe vehicle can be an indication of potential road icing problems. Suchinformation can be used to provide early warning to a driver ofpotentially dangerous conditions. Although the invention describedherein is related to land vehicles, many of these advances are equallyapplicable to other vehicles such as airplanes and even, in some cases,homes and buildings. The invention disclosed herein, therefore, is notlimited to automobiles or other land vehicles.

Road condition sensing is another field in which SAW technology can beapplied and the invention encompasses several embodiments of SAW roadcondition sensors.

The temperature and moisture content of the surface of a roadway arecritical parameters in determining the icing state of the roadway.Attempts have been made to measure the coefficient of friction between atire and the roadway by placing strain gages in the tire tread.Naturally, such strain gages are ideal for the application of SAWtechnology especially since they can be interrogated wirelessly from adistance and they require no power for operation. As discussed herein,SAW accelerometers can also perform this function. The measurement ofthe friction coefficient, however, is not predictive and the vehicleoperator is only able to ascertain the condition after the fact. BoostedSAW or RFID based transducers have the capability of being interrogatedas much as 100 feet from the interrogator. Therefore, the judiciousplacement of low-cost powerless SAW or RFID temperature and humiditysensors in and/or on the roadway at critical positions can provide anadvance warning to vehicle operators that the road ahead is slippery.Such devices are very inexpensive and therefore could be placed atfrequent intervals along a highway.

An infrared sensor that looks down the highway in front of the vehiclecan actually measure the road temperature prior to the vehicle travelingon that part of the roadway. This system also would not give sufficientwarning if the operator waited for the occurrence of a frozen roadway.The probability of the roadway becoming frozen, on the other hand, canbe predicted long before it occurs, in most cases, by watching the trendin the temperature. Once vehicle-to-vehicle communications are common,roadway icing conditions can be communicated between vehicles.

Some lateral control of the vehicle can also be obtained from SAWtransducers or electronic RFID tags placed down the center of the lane,either above the vehicles and/or in the roadway, for example. A vehiclehaving two receiving antennas, for example, approaching such devices,through triangulation or direct proportion, is able to determine thelateral location of the vehicle relative to these SAW devices. If thevehicle also has an accurate map of the roadway, the identificationnumber associated with each such device can be used to obtain highlyaccurate longitudinal position determinations. Ultimately, the SAWdevices can be placed on structures beside the road and perhaps on everymile or tenth of a mile marker. If three antennas are used, as discussedherein, the distances from the vehicle to the SAW device can bedetermined. These SAW devices can be powered in order to stay belowcurrent FCC power transmission limits. Such power can be supplied by aphotocell, energy harvesting where applicable, by a battery or powerconnection.

Electronic RFID tags are also suitable for lateral and longitudinalpositioning purposes, however, the range available for currentelectronic RFID systems can be less than that of SAW-based systemsunless either are powered. On the other hand, as disclosed in U.S. Pat.No. 6,748,797, the time-of-flight of the RFID system can be used todetermine the distance from the vehicle to the RFID tag. Because of theinherent delay in the SAW devices and its variation with temperature,accurate distance measurement is probably not practical based ontime-of-flight but somewhat less accurate distance measurements based onrelative time-of-arrival can be made. Even if the exact delay imposed bythe SAW device was accurately known at one temperature, such devices areusually reasonably sensitive to changes in temperature, hence they makegood temperature sensors, and thus the accuracy of the delay in the SAWdevice is more difficult to maintain. An interesting variation of anelectronic RFID that is particularly applicable to this and otherapplications of this invention is described in A. Pohl, L. Reindl, “Newpassive sensors”, Proc. 16th IEEE Instrumentation and MeasurementTechnology Conf., IMTC/99, 1999, pp. 1251-1255.

Many SAW devices are based on lithium niobate or similar strongpiezoelectric materials. Such materials have high thermal expansioncoefficients. An alternate material is quartz that has a very lowthermal expansion coefficient. However, its piezoelectric properties areinferior to lithium niobate. One solution to this problem is to uselithium niobate as the coupling system between the antenna and thematerial or substrate upon which the surface acoustic wave travels. Inthis manner, the advantages of a low thermal expansion coefficientmaterial can be obtained while using the lithium niobate for its strongpiezoelectric properties. Other useful materials such as Langasite™ haveproperties that are intermediate between lithium niobate and quartz.

The use of SAW tags as an accurate precise positioning system asdescribed above would be applicable for accurate vehicle location, asdiscussed in U.S. Pat. No. 6,370,475, for lanes in tunnels, for example,or other cases where loss of satellite lock, and thus the primaryvehicle location system, is common.

The various technologies discussed above can be used in combination. Theelectronic RFID tag can be incorporated into a SAW tag providing asingle device that provides both a quick reflection of the radiofrequency waves as well as a re-transmission at a later time. Thismarriage of the two technologies permits the strengths of eachtechnology to be exploited in the same device. For most of theapplications described herein, the cost of mounting such a tag in avehicle or on the roadway far exceeds the cost of the tag itself.Therefore, combining the two technologies does not significantly affectthe cost of implementing tags onto vehicles or roadways or side highwaystructures.

A variation of this design is to use an RF circuit such as in an RFID toserve as an energy source. One design could be for the RFID to operatewith directional antennas at a relatively high frequency such as 2.4GHz. This can be primarily used to charge a capacitor to provide theenergy for boosting the signal from the SAW sensor using circuitry suchas a circulator discussed below. The SAW sensor can operate at a lowerfrequency, such as 400 MHz, permitting it to not interfere with theenergy transfer to the RF circuit and also permit the signal to travelbetter to the receiver since it will be difficult to align the antennaat all times with the interrogator. Also, by monitoring the reception ofthe RF signal, the angular position of the tire can be determined andthe SAW circuit designed so that it only transmits when the antennas arealigned or when the vehicle is stationary. Many other opportunities nowpresent themselves with the RF circuit operating at a differentfrequency from the SAW circuit which will now be obvious to one skilledin the art.

An alternate method to the electronic RFID tag is to simply use a radaror lidar reflector and measure the time-of-flight to the reflector andback. The reflector can even be made of a series of reflecting surfacesdisplaced from each other to achieve some simple coding. It should beunderstood that RFID antennas can be similarly configured. Animprovement would be to polarize the radiation and use a reflector thatrotates the polarization angle allowing the reflector to be more easilyfound among other reflecting objects.

Another field in which SAW technology can be applied is for“ultrasound-on-a-surface” type of devices. U.S. Pat. No. 5,629,681,assigned to the current assignee herein and incorporated by referenceherein, describes many uses of ultrasound in a tube. Many of theapplications are also candidates for ultrasound-on-a-surface devices. Inthis case, a micro-machined SAW device will in general be replaced by amuch larger structure.

Based on the frequency and power available, and on FCC limitations, SAWor RFID or similar devices can be designed to permit transmissiondistances of many feet especially if minimal power is available. SinceSAW and RFID devices can measure both temperature and humidity, they arealso capable of monitoring road conditions in front of and around avehicle. Thus, a properly equipped vehicle can determine the roadconditions prior to entering a particular road section if such SAWdevices are embedded in the road surface or on mounting structures closeto the road surface as shown at 60 in FIG. 5. Such devices could provideadvance warning of freezing conditions, for example. Although at 60miles per hour such devices may only provide a one second warning ifpowered or if the FCC revises permitted power levels, this can besufficient to provide information to a driver to prevent dangerousskidding. Additionally, since the actual temperature and humidity can bereported, the driver will be warned prior to freezing of the roadsurface. SAW device 60 is shown in FIG. 5A. With vehicle-to-vehiclecommunication, the road conditions can be communicated as needed.

If a SAW device 63 is placed in a roadway, as illustrated in FIG. 6, andif a vehicle 68 has two receiving antennas 61 and 62, an interrogatorcan transmit a signal from either of the two antennas and at a latertime, the two antennas will receive the transmitted signal from the SAWdevice 63. By comparing the arrival time of the two received pulses, theposition of vehicle 68 on a lane of the roadway can preciselycalculated. If the SAW device 63 has an identification code encoded intothe returned signal generated thereby, then a processor in the vehicle68 can determine its position on the surface of the earth, provided aprecise map is available such as by being stored in the processor'smemory. If another antenna 66 is provided, for example, at the rear ofthe vehicle 68, then the longitudinal position of the vehicle 68 canalso be accurately determined as the vehicle 68 passes the SAW device63.

The SAW device 63 does not have to be in the center of the road.Alternate locations for positioning of the SAW device 63 are onoverpasses above the road and on poles such as 64 and 65 on theroadside. For such cases, a source of power may be required. Such asystem has an advantage over a competing system using radar andreflectors in that it is easier to measure the relative time between thetwo received pulses than it is to measure time-of-flight of a radarsignal to a reflector and back. Such a system operates in all weatherconditions and is known as a precise location system. Eventually, such aSAW device 63 can be placed every tenth of a mile along the roadway orat some other appropriate spacing. For the radar or laser radarreflection system, the reflectors can be active devices that provideenvironmental information in addition to location information to theinterrogating vehicle.

If a vehicle is being guided by a DGPS and an accurate map system suchas disclosed in U.S. Pat. No. 6,405,132 is used, a problem arises whenthe GPS receiver system looses satellite lock as would happen when thevehicle enters a tunnel, for example. If a precise location system asdescribed above is placed at the exit of the tunnel, then the vehiclewill know exactly where it is and can re-establish satellite lock in aslittle as one second rather than typically 15 seconds as might otherwisebe required. Other methods making use of the cell phone system can beused to establish an approximate location of the vehicle suitable forrapid acquisition of satellite lock as described in G. M. Djuknic, R. E.Richton “Geolocation and Assisted GPS”, Computer Magazine, February2001, IEEE Computer Society, which is incorporated by reference hereinin its entirety. An alternate location system is described in U.S. Pat.No. 6,480,788.

More particularly, geolocation technologies that rely exclusively onwireless networks such as time of arrival, time difference of arrival,angle of arrival, timing advance, and multipath fingerprinting, as isknown to those skilled in the art, offer a shorter time-to-first-fix(TTFF) than GPS. They also offer quick deployment and continuoustracking capability for navigation applications, without the addedcomplexity and cost of upgrading or replacing any existing GPS receiverin vehicles. Compared to either mobile-station-based, stand-alone GPS ornetwork-based geolocation, assisted-GPS (AGPS) technology offerssuperior accuracy, availability and coverage at a reasonable cost. AGPSfor use with vehicles can comprise a communications unit with a minimalcapability GPS receiver arranged in the vehicle, an AGPS server with areference GPS receiver that can simultaneously “see” the same satellitesas the communications unit and a wireless network infrastructureconsisting at least of base stations and a mobile switching center. Thenetwork can accurately predict the GPS signal the communication unitwill receive and convey that information to the mobile unit such as avehicle, greatly reducing search space size and shortening the TTFF fromminutes to a second or less. In addition, an AGPS receiver in thecommunication unit can detect and demodulate weaker signals than thosethat conventional GPS receivers require. Because the network performsthe location calculations, the communication unit only needs to containa scaled-down GPS receiver. It is accurate within about 15 meters whenthey are outdoors, an order of magnitude more sensitive thanconventional GPS. Of course with the additional of differentialcorrections and carrier phase corrections, the location accuracy can beimproved to centimeters.

Since an AGPS server can obtain the vehicle's position from the mobileswitching center, at least to the level of cell and sector, and at thesame time monitor signals from GPS satellites seen by mobile stations,it can predict the signals received by the vehicle for any given time.Specifically, the server can predict the Doppler shift due to satellitemotion of GPS signals received by the vehicle, as well as other signalparameters that are a function of the vehicle's location. In a typicalsector, uncertainty in a satellite signal's predicted time of arrival atthe vehicle is about ±5 μs, which corresponds to ±5 chips of the GPScoarse acquisition (C/A) code. Therefore, an AGPS server can predict thephase of the pseudorandom noise (PRN) sequence that the receiver shoulduse to despread the C/A signal from a particular satellite (each GPSsatellite transmits a unique PRN sequence used for range measurements)and communicate that prediction to the vehicle. The search space for theactual Doppler shift and PRN phase is thus greatly reduced, and the AGPSreceiver can accomplish the task in a fraction of the time required byconventional GPS receivers. Further, the AGPS server maintains aconnection with the vehicle receiver over the wireless link, so therequirement of asking the communication unit to make specificmeasurements, collect the results and communicate them back is easilymet. After despreading and some additional signal processing, an AGPSreceiver returns back “pseudoranges” (that is, ranges measured withouttaking into account the discrepancy between satellite and receiverclocks) to the AGPS server, which then calculates the vehicle'slocation. The vehicle can even complete the location fix itself withoutreturning any data to the server. Further discussion of cellularlocation-based systems can be found in Caffery, J. J. Wireless Locationin CDMA Cellular Radio Systems, Kluwer Academic Publishers, 1999, ISBN:0792377036.

Sensitivity assistance, also known as modulation wipe-off, providesanother enhancement to detection of GPS signals in the vehicle'sreceiver. The sensitivity-assistance message contains predicted databits of the GPS navigation message, which are expected to modulate theGPS signal of specific satellites at specified times. The mobile stationreceiver can therefore remove bit modulation in the received GPS signalprior to coherent integration. By extending coherent integration beyondthe 20-ms GPS data-bit period (to a second or more when the receiver isstationary and to 400 ms when it is fast-moving) this approach improvesreceiver sensitivity. Sensitivity assistance provides an additional3-to-4-dB improvement in receiver sensitivity. Because some of the gainprovided by the basic assistance (code phases and Doppler shift values)is lost when integrating the GPS receiver chain into a mobile system,this can prove crucial to making a practical receiver.

Achieving optimal performance of sensitivity assistance in TIA/EIA-95CDMA systems is relatively straightforward because base stations andmobiles synchronize with GPS time. Given that global system for mobilecommunication (GSM), time division multiple access (TDMA), or advancedmobile phone service (AMPS) systems do not maintain such stringentsynchronization, implementation of sensitivity assistance and AGPStechnology in general will require novel approaches to satisfy thetiming requirement. The standardized solution for GSM and TDMA adds timecalibration receivers in the field (location measurement units) that canmonitor both the wireless-system timing and GPS signals used as a timingreference.

Many factors affect the accuracy of geolocation technologies, especiallyterrain variations such as hilly versus flat and environmentaldifferences such as urban versus suburban versus rural. Other factors,like cell size and interference, have smaller but noticeable effects.Hybrid approaches that use multiple geolocation technologies appear tobe the most robust solution to problems of accuracy and coverage.

AGPS provides a natural fit for hybrid solutions since it uses thewireless network to supply assistance data to GPS receivers in vehicles.This feature makes it easy to augment the assistance-data message withlow-accuracy distances from receiver to base stations measured by thenetwork equipment. Such hybrid solutions benefit from the high densityof base stations in dense urban environments, which are hostile to GPSsignals. Conversely, rural environments, where base stations are tooscarce for network-based solutions to achieve high accuracy, provideideal operating conditions for AGPS because GPS works well there.

From the above discussion, AGPS can be a significant part of thelocation determining system on a vehicle and can be used to augmentother more accurate systems such as DGPS and a precise positioningsystem based on road markers or signature matching as discussed aboveand in patents assigned to Intelligent Technologies International.

SAW transponders can also be placed in the license plates 67 (FIG. 6) ofall vehicles at nominal cost. An appropriately equipped automobile canthen determine the angular location of vehicles in its vicinity. If athird antenna 66 is placed at the center of the vehicle front, then amore accurate indication of the distance to a license plate of apreceding vehicle can also be obtained as described above. Thus, onceagain, a single interrogator coupled with multiple antenna systems canbe used for many functions. Alternately, if more than one SAWtransponder is placed spaced apart on a vehicle and if two antennas areon the other vehicle, then the direction and position of theSAW-equipped vehicle can be determined by the receiving vehicle. Thevehicle-mounted SAW or RFID device can also transmit information aboutthe vehicle on which it is mounted such as the type of vehicle (car,van, SUV, truck, emergency vehicle etc.) as well as its weight and/ormass. One problem with many of the systems disclosed above results fromthe low power levels permitted by the FCC. Thus changes in FCCregulations may be required before some of them can be implemented in apowerless mode.

A general SAW temperature and pressure gage which can be wireless andpowerless is shown generally at 70 located in the sidewall 73 of a fluidcontainer 74 in FIG. 7. A pressure sensor 71 is located on the inside ofthe container 74, where it measures deflection of the container wall,and the fluid temperature sensor 72 on the outside. The temperaturemeasuring SAW 70 can be covered with an insulating material to avoid theinfluence of the ambient temperature outside of the container 74.

A SAW load sensor can also be used to measure load in the vehiclesuspension system powerless and wirelessly as shown in FIG. 8. FIG. 8Aillustrates a strut 75 such as either of the rear struts of the vehicleof FIG. 8. A coil spring 80 stresses in torsion as the vehicleencounters disturbances from the road and this torsion can be measuredusing SAW strain gages as described in U.S. Pat. No. 5,585,571 formeasuring the torque in shafts. This concept is also described in U.S.Pat. No. 5,714,695. Use of SAW strain gages to measure the torsionalstresses in a spring, as shown in FIG. 8B, and in particular in anautomobile suspension spring, is believed to have been first disclosedby the inventors herein, or other of the assignee's employees or agents.In FIG. 8B, the strain measured by SAW strain gage 78 is subtracted fromthe strain measured by SAW strain gage 77 to get the temperaturecompensated strain in spring 76.

Since a portion of the dynamic load is also carried by the shockabsorber, the SAW strain gages 77 and 78 will only measure the steady oraverage load on the vehicle. However, additional SAW strain gages 79 canbe placed on a piston rod 81 of the shock absorber to obtain the dynamicload. These load measurements can then be used for active or passivevehicle damping or other stability control purposes. Knowing the dynamicload on the vehicle coupled with measuring the response of the vehicleor of the load of an occupant on a seat also permits a determination ofthe vehicle's inertial properties and, in the case of the seat weightsensor, of the mass of an occupant and the state of the seat belt (is itbuckled and what load is it adding to the seat load sensors).

FIG. 9 illustrates a vehicle passenger compartment, and the enginecompartment, with multiple SAW or RFID temperature sensors 85. SAWtemperature sensors can be distributed throughout the passengercompartment, such as on the A-pillar, on the B-pillar, on the steeringwheel, on the seat, on the ceiling, on the headliner, and on thewindshield, rear and side windows and generally in the enginecompartment. These sensors, which can be independently coded withdifferent IDs and/or different delays, can provide an accuratemeasurement of the temperature distribution within the vehicle interior.RFID switches as discussed below can also be used to isolate one devicefrom another. Such a system can be used to tailor the heating and airconditioning system based on the temperature at a particular location inthe passenger compartment. If this system is augmented with occupantsensors, then the temperature can be controlled based on seat occupancyand the temperature at that location. If the occupant sensor system isbased on ultrasonics, then the temperature measurement system can beused to correct the ultrasonic occupant sensor system for the speed ofsound within the passenger compartment. Without such a correction, theerror in the sensing system can be as large as about 20 percent.

In one implementation, SAW temperature and other sensors can be madefrom PVDF film and incorporated within the ultrasonic transducerassembly. For the 40 kHz ultrasonic transducer case, for example, theSAW temperature sensor would return the several pulses sent to drive theultrasonic transducer to the control circuitry using the same wires usedto transmit the pulses to the transducer after a delay that isproportional to the temperature within the transducer housing. Thus, avery economical device can add this temperature sensing function usingmuch of the same hardware that is already present for the occupantsensing system. Since the frequency is low, PVDF could be fabricatedinto a very low cost temperature sensor for this purpose. Otherpiezoelectric materials can of course also be used.

Note, the use of PVDF as a piezoelectric material for wired and wirelessSAW transducers or sensors is an important disclosure of at least one ofthe inventions disclosed herein. Such PVDF SAW devices can be used aschemical, biological, temperature, pressure and other SAW sensors aswell as for switches. Such devices are very inexpensive to manufactureand are suitable for many vehicle-mounted devices as well as for othernon-vehicle-mounted sensors. Disadvantages of PVDF stem from the lowerpiezoelectric constant (compared with lithium niobate) and the lowacoustic wave velocity thus limiting the operating frequency. The keyadvantage is very low cost. When coupled with plastic electronics(plastic chips), it now becomes very economical to place sensorsthroughout the vehicle for monitoring a wide range of parameters such astemperature, pressure, chemical concentration etc. In particularimplementations, an electronic nose based on SAW or RFID technology andneural networks can be implemented in either a wired or wireless mannerfor the monitoring of cargo containers or other vehicle interiors (orbuilding interiors) for anti-terrorist or security purposes. See, forexample, Reznik, A. M. “Associative Memories for Chemical Sensing”, IEEE2002 ICONIP, p. 2630-2634, vol. 5. In this manner, other sensors can becombined with the temperature sensors 85, or used separately, to measurecarbon dioxide, carbon monoxide, alcohol, biological agents, radiation,humidity or other desired chemicals or agents as discussed above. Note,although the examples generally used herein are from the automotiveindustry, many of the devices disclosed herein can be advantageouslyused with other vehicles including trucks, boats, airplanes and shippingcontainers.

The SAW temperature sensors 85 provide the temperature at their mountinglocation to a processor unit 83 via an interrogator with the processorunit 83 including appropriate control algorithms for controlling theheating and air conditioning system based on the detected temperatures.The processor unit 83 can control, e.g., which vents in the vehicle areopen and closed, the flow rate through vents and the temperature of airpassing through the vents. In general, the processor unit 83 can controlwhatever adjustable components are present or form part of the heatingand air conditioning system.

In FIG. 9 a child seat 84 is illustrated on the rear vehicle seat. Thechild seat 84 can be fabricated with one or more RFID tags or SAW tags(not shown). The RFID and SAW tag(s) can be constructed to provideinformation on the occupancy of the child seat, i.e., whether a child ispresent, based on the weight, temperature, and/or any other measurableparameter. Also, the mere transmission of waves from the RFID or SAWtag(s) on the child seat 84 would be indicative of the presence of achild seat. The RFID and SAW tag(s) can also be constructed to provideinformation about the orientation of the child seat 84, i.e., whether itis facing rearward or forward. Such information about the presence andoccupancy of the child seat and its orientation can be used in thecontrol of vehicular systems, such as the vehicle airbag system orheating or air conditioning system, especially useful when a child isleft in a vehicle. In this case, a processor would control the airbag orHVAC system and would receive information from the RFID and SAW tag(s)via an interrogator.

There are many applications for which knowledge of the pitch and/or rollorientation of a vehicle or other object is desired. An accurate tiltsensor can be constructed using SAW devices. Such a sensor isillustrated in FIG. 10A and designated 86. This sensor 86 can utilize asubstantially planar and rectangular mass 87 and four supporting SAWdevices 88 which are sensitive to gravity. For example, the mass 87 actsto deflect a membrane on which the SAW device 88 resides therebystraining the SAW device 88. Other properties can also be used for atilt sensor such as the direction of the earth's magnetic field. SAWdevices 88 are shown arranged at the corners of the planar mass 87, butit must be understood that this arrangement is an exemplary embodimentonly and not intended to limit the invention. A fifth SAW device 89 canbe provided to measure temperature. By comparing the outputs of the fourSAW devices 88, the pitch and roll of the automobile can be measured.This sensor 86 can be used to correct errors in the SAW rate gyrosdescribed above. If the vehicle has been stationary for a period oftime, the yaw SAW rate gyro can initialized to 0 and the pitch and rollSAW gyros initialized to a value determined by the tilt sensor of FIG.10A. Many other geometries of tilt sensors utilizing one or more SAWdevices can now be envisioned for automotive and other applications.

In particular, an alternate preferred configuration is illustrated inFIG. 10B where a triangular geometry is used. In this embodiment, theplanar mass is triangular and the SAW devices 88 are arranged at thecorners, although as with FIG. 10A, this is a non-limiting, preferredembodiment.

Either of the SAW accelerometers described above can be utilized forcrash sensors as shown in FIG. 11. These accelerometers have asubstantially higher dynamic range than competing accelerometers nowused for crash sensors such as those based on MEMS silicon springs andmasses and others based on MEMS capacitive sensing. As discussed above,this is partially a result of the use of frequency or phase shifts whichcan be measured over a very wide range. Additionally, many conventionalaccelerometers that are designed for low acceleration ranges are unableto withstand high acceleration shocks without breaking. This placespractical limitations on many accelerometer designs so that the stressesin the silicon are not excessive. Also for capacitive accelerometers,there is a narrow limit over which distance, and thus acceleration, canbe measured.

The SAW accelerometer for this particular crash sensor design is housedin a container 96 which is assembled into a housing 97 and covered witha cover 98. This particular implementation shows a connector 99indicating that this sensor would require power and the response wouldbe provided through wires. Alternately, as discussed for other devicesabove, the connector 99 can be eliminated and the information and powerto operate the device transmitted wirelessly. Also, power can besupplied thorough a connector and stored in a capacitor while theinformation is transmitted wirelessly thus protecting the system from awire failure during a crash when the sensor is mounted in the crushzone. Such sensors can be used as frontal, side or rear impact sensors.They can be used in the crush zone, in the passenger compartment or anyother appropriate vehicle location. If two such sensors are separatedand have appropriate sensitive axes, then the angular acceleration ofthe vehicle can also be determined. Thus, for example, forward-facingaccelerometers mounted in the vehicle side doors can be used to measurethe yaw acceleration of the vehicle. Alternately, two vertical sensitiveaxis accelerometers in the side doors can be used to measure the rollacceleration of vehicle, which would be useful for rollover sensing.

U.S. Pat. No. 6,615,656, assigned to the current assignee of thisinvention, and the description below, provides multiple apparatus fordetermining the amount of liquid in a tank. Using the SAW pressuredevices of this invention, multiple pressure sensors can be placed atappropriate locations within a fuel tank to measure the fluid pressureand thereby determine the quantity of fuel remaining in the tank. Thiscan be done both statically and dynamically. This is illustrated in FIG.12. In this example, four SAW pressure transducers 100 are placed on thebottom of the fuel tank and one SAW pressure transducer 101 is placed atthe top of the fuel tank to eliminate the effects of vapor pressurewithin tank. Using neural networks, or other pattern recognitiontechniques, the quantity of fuel in the tank can be accuratelydetermined from these pressure readings in a manner similar to thatdescribed the '656 patent and below. The SAW measuring deviceillustrated in FIG. 12A combines temperature and pressure measurementsin a single unit using parallel paths 102 and 103 in the same manner asdescribed above.

FIG. 13A shows a schematic of a prior art airbag module deploymentscheme in which sensors, which detect data for use in determiningwhether to deploy an airbag in the airbag module, are wired to anelectronic control unit (ECU) and a command to initiate deployment ofthe airbag in the airbag module is sent wirelessly. By contrast, asshown in FIG. 13B, in accordance with an invention herein, the sensorsare wirelessly connected to the electronic control unit and thustransmit data wirelessly. The ECU is however wired to the airbag module.The ECU could also be connected wirelessly to the airbag module.Alternately, a safety bus can be used in place of the wirelessconnection.

SAW sensors also have applicability to various other sectors of thevehicle, including the powertrain, chassis, and occupant comfort andconvenience. For example, SAW and RFID sensors have applicability tosensors for the powertrain area including oxygen sensors, gear-toothHall effect sensors, variable reluctance sensors, digital speed andposition sensors, oil condition sensors, rotary position sensors, lowpressure sensors, manifold absolute pressure/manifold air temperature(MAP/MAT) sensors, medium pressure sensors, turbo pressure sensors,knock sensors, coolant/fluid temperature sensors, and transmissiontemperature sensors.

SAW sensors for chassis applications include gear-tooth Hall effectsensors, variable reluctance sensors, digital speed and positionsensors, rotary position sensors, non-contact steering position sensors,and digital ABS (anti-lock braking system) sensors. In oneimplementation, a Hall Effect tire pressure monitor comprises a magnetthat rotates with a vehicle wheel and is sensed by a Hall Effect devicewhich is attached to a SAW or RFID device that is wirelesslyinterrogated. This arrangement eliminates the need to run a wire intoeach wheel well.

SAW sensors for the occupant comfort and convenience field include lowtire pressure sensors, HVAC temperature and humidity sensors, airtemperature sensors, and oil condition sensors.

SAW sensors also have applicability such areas as controllingevaporative emissions, transmission shifting, mass air flow meters,oxygen, NOx and hydrocarbon sensors. SAW based sensors are particularlyuseful in high temperature environments where many other technologiesfail.

SAW sensors can facilitate compliance with U.S. regulations concerningevaporative system monitoring in vehicles, through a SAW fuel vaporpressure and temperature sensors that measure fuel vapor pressure withinthe fuel tank as well as temperature. If vapors leak into theatmosphere, the pressure within the tank drops. The sensor notifies thesystem of a fuel vapor leak, resulting in a warning signal to the driverand/or notification to a repair facility, vehicle manufacturer and/orcompliance monitoring facility. This application is particularlyimportant since the condition within the fuel tank can be ascertainedwirelessly reducing the chance of a fuel fire in an accident. The sameinterrogator that monitors the tire pressure SAW sensors can alsomonitor the fuel vapor pressure and temperature sensors resulting insignificant economies.

A SAW humidity sensor can be used for measuring the relative humidityand the resulting information can be input to the engine managementsystem or the heating, ventilation and air conditioning (HVAC) systemfor more efficient operation. The relative humidity of the air enteringan automotive engine impacts the engine's combustion efficiency; i.e.,the ability of the spark plugs to ignite the fuel/air mixture in thecombustion chamber at the proper time. A SAW humidity sensor in thiscase can measure the humidity level of the incoming engine air, helpingto calculate a more precise fuel/air ratio for improved fuel economy andreduced emissions.

Dew point conditions are reached when the air is fully saturated withwater. When the cabin dew point temperature matches the windshield glasstemperature, water from the air condenses quickly, creating frost orfog. A SAW humidity sensor with a temperature-sensing element and awindow glass-temperature-sensing element can prevent the formation ofvisible fog formation by automatically controlling the HVAC system.

FIG. 14 illustrates the placement of a variety of sensors, primarilyaccelerometers and/or gyroscopes, which can be used to diagnose thestate of the vehicle itself. Sensor 105 can be located in the headlineror attached to the vehicle roof above the side door. Typically, therecan be two such sensors one on either side of the vehicle. Sensor 106 isshown in a typical mounting location midway between the sides of thevehicle attached to or near the vehicle roof above the rear window.Sensor 109 is shown in a typical mounting location in the vehicle trunkadjacent the rear of the vehicle. One, two or three such sensors can beused depending on the application. If three such sensors are used,preferably one would be adjacent each side of vehicle and one in thecenter. Sensor 107 is shown in a typical mounting location in thevehicle door and sensor 108 is shown in a typical mounting location onthe sill or floor below the door. Sensor 110, which can be also multiplesensors, is shown in a typical mounting location forward in the crushzone of the vehicle. Finally, sensor 1 can measure the acceleration ofthe firewall or instrument panel and is located thereon generally midwaybetween the two sides of the vehicle. If three such sensors are used,one would be adjacent each vehicle side and one in the center. An IMUwould serve basically the same functions.

In general, sensors 105-111 provide a measurement of the state of thevehicle, such as its velocity, acceleration, angular orientation ortemperature, or a state of the location at which the sensor is mounted.Thus, measurements related to the state of the sensor would includemeasurements of the acceleration of the sensor, measurements of thetemperature of the mounting location as well as changes in the state ofthe sensor and rates of changes of the state of the sensor. As such, anydescribed use or function of the sensors 105-111 above is merelyexemplary and is not intended to limit the form of the sensor or itsfunction. Thus, these sensors may or may not be SAW or RFID sensors andmay be powered or unpowered and may transmit their information through awire harness, a safety or other bus or wirelessly.

Each of the sensors 105-111 may be single axis, double axis or triaxialaccelerometers and/or gyroscopes typically of the MEMS type. One or morecan be IMUs. These sensors 105-111 can either be wired to the centralcontrol module or processor directly wherein they would receive powerand transmit information, or they could be connected onto the vehiclebus or, in some cases, using RFID, SAW or similar technology, thesensors can be wireless and would receive their power through RF fromone or more interrogators located in the vehicle. In this case, theinterrogators can be connected either to the vehicle bus or directly tocontrol module. Alternately, an inductive or capacitive power and/orinformation transfer system can be used.

One particular implementation will now be described. In this case, eachof the sensors 105-111 is a single or dual axis accelerometer. They aremade using silicon micromachined technology such as described in U.S.Pat. No. 5,121,180 and U.S. Pat. No. 5,894,090. These are onlyrepresentative patents of these devices and there exist more than 100other relevant U.S. patents describing this technology. Commerciallyavailable MEMS gyroscopes such as from Systron Doner have accuracies ofapproximately one degree per second. In contrast, optical gyroscopestypically have accuracies of approximately one degree per hour.Unfortunately, the optical gyroscopes are believed to be expensive forautomotive applications. However new developments by the currentassignee are reducing this cost and such gyroscopes are likely to becomecost effective in a few years. On the other hand, typical MEMSgyroscopes are not sufficiently accurate for many control applicationsunless corrected using location technology such as precise positioningor GPS-based systems as described elsewhere herein.

The angular rate function can be obtained by placing accelerometers attwo separated, non-co-located points in a vehicle and using thedifferential acceleration to obtain an indication of angular motion andangular acceleration. From the variety of accelerometers shown in FIG.14, it can be appreciated that not only will all accelerations of keyparts of the vehicle be determined, but the pitch, yaw and roll angularrates can also be determined based on the accuracy of theaccelerometers. By this method, low cost systems can be developed which,although not as accurate as the optical gyroscopes, are considerablymore accurate than uncorrected conventional MEMS gyroscopes.Alternately, it has been found that from a single package containing upto three low cost MEMS gyroscopes and three low cost MEMSaccelerometers, when carefully calibrated, an accurate inertialmeasurement unit (IMU) can be constructed that performs as well as unitscosting a great deal more. Such a package is sold by CrossbowTechnology, Inc. 41 Daggett Dr., San Jose, Calif. 95134. If this IMU iscombined with a GPS system and sometimes other vehicle sensor inputsusing a Kalman filter, accuracy approaching that of expensive militaryunits can be achieved. A preferred IMU that uses a single device tosense both accelerations in three directions and angular rates aboutthree axis is described in U.S. Pat. No. 4,711,125. Although this devicehas been available for many years, it has not been applied to vehiclesensing and in particular automobile vehicle sensing for location andnavigational purposes.

Instead of using two accelerometers at separate locations on thevehicle, a single conformal MEMS-IDT gyroscope may be used. Such aconformal MEMS-IDT gyroscope is described in a paper by V. K. Varadan,“Conformal MEMS-IDT Gyroscopes and Their Comparison With Fiber OpticGyro”, Proceedings of SPIE Vol. 3990 (2000). The MEMS-IDT gyroscope isbased on the principle of surface acoustic wave (SAW) standing waves ona piezoelectric substrate. A surface acoustic wave resonator is used tocreate standing waves inside a cavity and the particles at theanti-nodes of the standing waves experience large amplitude ofvibrations, which serves as the reference vibrating motion for thegyroscope. Arrays of metallic dots are positioned at the anti-nodelocations so that the effect of Coriolis force due to rotation willacoustically amplify the magnitude of the waves. Unlike other MEMSgyroscopes, the MEMS-IDT gyroscope has a planar configuration with nosuspended resonating mechanical structures. Other SAW-based gyroscopesare also now under development.

The system of FIG. 14 using dual axis accelerometers, or the IMU Kalmanfilter system, therefore provides a complete diagnostic system of thevehicle itself and its dynamic motion. Such a system is far moreaccurate than any system currently available in the automotive market.This system provides very accurate crash discrimination since the exactlocation of the crash can be determined and, coupled with knowledge ofthe force deflection characteristics of the vehicle at the accidentimpact site, an accurate determination of the crash severity and thusthe need for occupant restraint deployment can be made. Similarly, thetendency of a vehicle to rollover can be predicted in advance andsignals sent to the vehicle steering, braking and throttle systems toattempt to ameliorate the rollover situation or prevent it. In the eventthat it cannot be prevented, the deployment side curtain airbags can beinitiated in a timely manner. Additionally, the tendency of the vehicleto the slide or skid can be considerably more accurately determined andagain the steering, braking and throttle systems commanded to minimizethe unstable vehicle behavior. Thus, through the deployment ofinexpensive accelerometers at a variety of locations in the vehicle, orthe IMU Kalman filter system, significant improvements are made invehicle stability control, crash sensing, rollover sensing and resultingoccupant protection technologies.

As mentioned above, the combination of the outputs from theseaccelerometer sensors and the output of strain gage weight sensors in avehicle seat, or in or on a support structure of the seat, can be usedto make an accurate assessment of the occupancy of the seat anddifferentiate between animate and inanimate occupants as well asdetermining where in the seat the occupants are sitting. This can bedone by observing the acceleration signals from the sensors of FIG. 14and simultaneously the dynamic strain gage measurements fromseat-mounted strain gages. The accelerometers provide the input functionto the seat and the strain gages measure the reaction of the occupyingitem to the vehicle acceleration and thereby provide a method ofdetermining dynamically the mass of the occupying item and its location.This is particularly important during occupant position sensing during acrash event. By combining the outputs of the accelerometers and thestrain gages and appropriately processing the same, the mass and weightof an object occupying the seat can be determined as well as the grossmotion of such an object so that an assessment can be made as to whetherthe object is a life form such as a human being.

For this embodiment, a sensor, not shown, that can be one or more straingage weight sensors, is mounted on the seat or in connection with theseat or its support structure. Suitable mounting locations and forms ofweight sensors are discussed in the current assignee's U.S. Pat. No.6,242,701 and contemplated for use in the inventions disclosed herein aswell. The mass or weight of the occupying item of the seat can thus bemeasured based on the dynamic measurement of the strain gages withoptional consideration of the measurements of accelerometers on thevehicle, which are represented by any of sensors 105-111.

A SAW Pressure Sensor can also be used with bladder weight sensorspermitting that device to be interrogated wirelessly and without theneed to supply power. Similarly, a SAW device can be used as a generalswitch in a vehicle and in particular as a seatbelt buckle switchindicative of seatbelt use. SAW devices can also be used to measureseatbelt tension or the acceleration of the seatbelt adjacent to thechest or other part of the occupant and used to control the occupant'sacceleration during a crash. Such systems can be boosted as disclosedherein or not as required by the application. These inventions aredisclosed in patents and patent applications of the current assignee.

The operating frequency of SAW devices has hereto for been limited toless that about 500 MHz due to problems in lithography resolution, whichof course is constantly improving and currently SAW devices based onlithium niobate are available that operate at 2.4 GHz. This lithographyproblem is related to the speed of sound in the SAW material. Diamondhas the highest speed of sound and thus would be an ideal SAW material.However, diamond is not piezoelectric. This problem can be solvedpartially by using a combination or laminate of diamond and apiezoelectric material. Recent advances in the manufacture of diamondfilms that can be combined with a piezoelectric material such as lithiumniobate promise to permit higher frequencies to be used since thespacing between the inter-digital transducer (IDT) fingers can beincreased for a given frequency. A particularly attractive frequency is2.4 GHz or Wi-Fi as the potential exists for the use of moresophisticated antennas such as the Yagi antenna or the Motia smartantenna that have more gain and directionality. In a differentdevelopment, SAW devices have been demonstrated that operate in the tensof GHz range using a novel stacking method to achieve the close spacingof the IDTs.

In a related invention, the driver can be provided with a keyless entrydevice, other RFID tag, smart card or cell phone with an RF transponderthat can be powerless in the form of an RFID or similar device, whichcan also be boosted as described herein. The interrogator determines theproximity of the driver to the vehicle door or other similar object suchas a building or house door or vehicle trunk. As shown in FIG. 15A, if adriver 118 remains within 1 meter, for example, from the door or trunklid 116, for example, for a time period such as 5 seconds, then the dooror trunk lid 116 can automatically unlock and ever open in someimplementations. Thus, as the driver 118 approaches the trunk with hisor her arms filled with packages 117 and pauses, the trunk canautomatically open (see FIG. 15B). Such a system would be especiallyvaluable for older people. Naturally, this system can also be used forother systems in addition to vehicle doors and trunk lids.

As shown in FIG. 15C, an interrogator 115 is placed on the vehicle,e.g., in the trunk 112 as shown, and transmits waves. When the keylessentry device 113, which contains an antenna 114 and a circuit includinga circulator 135 and a memory containing a unique ID code 136, is a setdistance from the interrogator 115 for a certain duration of time, theinterrogator 115 directs a trunk opening device 137 to open the trunklid 116 A SAW device can also be used as a wireless switch as shown inFIGS. 16A and 16B. FIG. 16A illustrates a surface 120 containing aprojection 122 on top of a SAW device 121. Surface material 120 couldbe, for example, the armrest of an automobile, the steering wheel airbagcover, or any other surface within the passenger compartment of anautomobile or elsewhere. Projection 122 will typically be a materialcapable of transmitting force to the surface of SAW device 121. As shownin FIG. 16B, a projection 123 may be placed on top of the SAW device124. This projection 123 permits force exerted on the projection 122 tocreate a pressure on the SAW device 124. This increased pressure changesthe time delay or natural frequency of the SAW wave traveling on thesurface of material. Alternately, it can affect the magnitude of thereturned signal. The projection 123 is typically held slightly out ofcontact with the surface until forced into contact with it.

An alternate approach is to place a switch across the IDT 127 as shownin FIG. 16C. If switch 125 is open, then the device will not return asignal to the interrogator. If it is closed, than the IDT 127 will actas a reflector sending a signal back to IDT 128 and thus to theinterrogator. Alternately, a switch 126 can be placed across the SAWdevice. In this case, a switch closure shorts the SAW device and nosignal is returned to the interrogator. For the embodiment of FIG. 16C,using switch 126 instead of switch 125, a standard reflector IDT wouldbe used in place of the IDT 127.

Most SAW-based accelerometers work on the principle of straining the SAWsurface and thereby changing either the time delay or natural frequencyof the system. An alternate novel accelerometer is illustrated FIG. 17Awherein a mass 130 is attached to a silicone rubber coating 131 whichhas been applied the SAW device. Acceleration of the mass in FIG. 17A inthe direction of arrow X changes the amount of rubber in contact withthe surface of the SAW device and thereby changes the damping, naturalfrequency or the time delay of the device. By this method, accuratemeasurements of acceleration below 1 G are readily obtained.Furthermore, this device can withstand high deceleration shocks withoutdamage. FIG. 17B illustrates a more conventional approach where thestrain in a beam 132 caused by the acceleration acting on a mass 133 ismeasured with a SAW strain sensor 134.

It is important to note that all of these devices have a high dynamicrange compared with most competitive technologies. In some cases, thisdynamic range can exceed 100,000 and up to 1,000,000 has been reported.This is the direct result of the ease with which frequency and phase canbe accurately measured.

A gyroscope, which is suitable for automotive applications, isillustrated in FIG. 18 and described in U.S. Pat. No. 6,516,665. ThisSAW-based gyroscope has applicability for the vehicle navigation,dynamic control, and rollover sensing among others.

Note that any of the disclosed applications can be interrogated by thecentral interrogator of this invention and can either be powered oroperated powerlessly as described in general above. Block diagrams ofthree interrogators suitable for use in this invention are illustratedin FIGS. 19A-19C. FIG. 19A illustrates a super heterodyne circuit andFIG. 19B illustrates a dual super heterodyne circuit. FIG. 19C operatesas follows. During the burst time two frequencies, F1 and F1+F2, aresent by the transmitter after being generated by mixing using oscillatorOsc. The two frequencies are needed by the SAW transducer where they aremixed yielding F2 which is modulated by the SAW and contains theinformation. Frequency (F1+F2) is sent only during the burst time whilefrequency F1 remains on until the signal F2 returns from the SAW. Thissignal is used for mixing. The signal returned from the SAW transducerto the interrogator is F1+F2 where F2 has been modulated by the SAWtransducer. It is expected that the mixing operations will result inabout 12 db loss in signal strength.

As discussed, theoretically a SAW can be used for any sensing functionprovided the surface across which the acoustic wave travels can bemodified in terms of its length, mass, elastic properties or anyproperty that affects the travel distance, speed, amplitude or dampingof the surface wave. Thus, gases and vapors can be sensed through theplacement of a layer on the SAW that absorbs the gas or vapor, forexample (a chemical sensor or electronic nose). Similarly, a radiationsensor can result through the placement of a radiation sensitive coatingon the surface of the SAW.

Normally, a SAW device is interrogated with a constant amplitude andfrequency RF pulse. This need not be the case and a modulated pulse canalso be used. If for example a pseudorandom or code modulation is used,then a SAW interrogator can distinguish its communication from that ofanother vehicle that may be in the vicinity. This doesn't totally solvethe problem of interrogating a tire that is on an adjacent vehicle butit does solve the problem of the interrogator being confused by thetransmission from another interrogator. This confusion can also bepartially solved if the interrogator only listens for a return signalbased on when it expects that signal to be present based on when it sentthe signal. That expectation can be based on the physical location ofthe tire relative to the interrogator which is unlikely to come from atire on an adjacent vehicle which only momentarily could be at anappropriate distance from the interrogator. The interrogator would ofcourse need to have correlation software in order to be able todifferentiate the relevant signals. The correlation technique alsopermits the interrogator to separate the desired signals from noisethereby improving the sensitivity of the correlator. An alternateapproach as discussed elsewhere herein is to combine a SAW sensor withan RFID switch where the switch is programmed to open or close based onthe receipt of the proper identification code.

As discussed elsewhere herein, the particular tire that is sending asignal can be determined if multiple antennas, such as three, eachreceive the signal. For a 500 MHz signal, for example, the wave lengthis about 60 cm. If the distance from a tire transmitter to each of threeantennas is on the order of one meter, then the relative distance fromeach antenna to the transmitter can be determined to within a fewcentimeters and thus the location of the transmitter can be found bytriangulation. If that location is not a possible location for a tiretransmitter, then the data can be ignored thus solving the problem of atransmitter from an adjacent vehicle being read by the wrong vehicleinterrogator. This is discussed in the parent '288 application withregard to solving the problem of a truck having 18 tires that all needto be monitored. Note also, each antenna can have associated with itsome simple circuitry that permits it to receive a signal, amplify it,change its frequency and retransmit it either through a wire of throughthe air to the interrogator thus eliminating the need for long andexpensive coax cables.

U.S. Pat. No. 6,622,567 describes a peak strain RFID technology baseddevice with the novelty being the use of a mechanical device thatrecords the peak strain experienced by the device. Like the system ofthe invention herein, the system does not require a battery and receivesits power from the RFID circuit. The invention described herein includesthe use of RFID based sensors either in the peak strain mode or in thepreferred continuous strain mode. This invention is not limited tomeasuring strain as SAW and RFID based sensors can be used for measuringmany other parameters including chemical vapor concentration,temperature, acceleration, angular velocity etc.

A key aspect of at least one of the inventions disclosed herein is theuse of an interrogator to wirelessly interrogate multiple sensingdevices thereby reducing the cost of the system since such sensors arein general inexpensive compared to the interrogator. The sensing devicesare preferably based of SAW and/or RFID technologies although othertechnologies are applicable.

1.3.1 Antenna Considerations

Antennas are a very important aspect to SAW and RFID wireless devicessuch as can be used in tire monitors, seat monitors, weight sensors,child seat monitors, fluid level sensors and similar devices or sensorswhich monitor, detect, measure, determine or derive physical propertiesor characteristics of a component in or on the vehicle or of an areanear the vehicle, as disclosed in the current assignee's patents andpending patent applications. Details about various antenna systems isset forth in section 1.3.1 of the parent '288 application.

1.4 Tire Monitoring

A thorough discussion about monitoring tires is set forth in the parent'288 application.

1.5 Occupant Sensing

Occupant or object presence and position sensing is another field inwhich SAW and/or RFID technology can be applied and the inventionsherein encompasses several embodiments of SAW and RFID occupant orobject presence and/or position sensors.

Many sensing systems are available to identify and locate occupants orother objects in a passenger compartment of the vehicle. Such sensorsinclude ultrasonic sensors, chemical sensors (e.g., carbon dioxide),cameras and other optical sensors, radar systems, heat and otherinfrared sensors, capacitance, magnetic or other field change sensors,etc. Most of these sensors require power to operate and returninformation to a central processor for analysis. An ultrasonic sensor,for example, may be mounted in or near the headliner of the vehicle andperiodically it transmits a burst of ultrasonic waves and receivesreflections of these waves from occupying items of the passenger seat.Current systems on the market are controlled by electronics in adedicated ECU.

FIG. 20 is a side view, with parts cutaway and removed of a vehicleshowing the passenger compartment containing a rear-facing child seat342 on a front passenger seat 343 and one mounting location for a firstembodiment of a vehicle interior monitoring system in accordance withthe invention. The interior monitoring system is capable of detectingthe presence of an object, determining the type of object, determiningthe location of the object, and/or determining another property orcharacteristic of the object. A property of the object could be thepresence or orientation of a child seat, the velocity of an adult andthe like. For example, the vehicle interior monitoring system candetermine that an object is present on the seat, that the object is achild seat and that the child seat is rear-facing. The vehicle interiormonitoring system could also determine that the object is an adult, thathe is drunk and that he is out-of-position relative to the airbag.

In this embodiment, six transducers 344, 345, 346, 347, 348 and 349 areused, although any number of transducers may be used. Each transducer344, 345, 346, 347, 348, 349 may comprise only a transmitter whichtransmits energy, waves or radiation, only a receiver which receivesenergy, waves or radiation, both a transmitter and a receiver capable oftransmitting and receiving energy, waves or radiation, an electric fieldsensor, a capacitive sensor, or a self-tuning antenna-based sensor,weight sensor, chemical sensor, motion sensor or vibration sensor, forexample.

Such transducers or receivers 344-349 may be of the type which emit orreceive a continuous signal, a time varying signal (such as a capacitoror electric field sensor) or a spatial varying signal such as in ascanning system. One particular type of radiation-receiving receiver foruse in the invention is a receiver capable of receiving electromagneticwaves.

When ultrasonic energy is used, transducer 345 can be used as atransmitter and transducers 344,346 as receivers. Naturally, othercombinations can be used such as where all transducers are transceivers(transmitters and receivers). For example, transducer 345 can beconstructed to transmit ultrasonic energy toward the front passengerseat, which is modified, in this case by the occupying item of thepassenger seat, i.e., the rear-facing child seat 342, and the modifiedwaves are received by the transducers 344 and 346, for example. A morecommon arrangement is where transducers 344, 345 and 346 are alltransceivers. Modification of the ultrasonic energy may constitutereflection of the ultrasonic energy as the ultrasonic energy isreflected back by the occupying item of the seat. The waves received bytransducers 344 and 346 vary with time depending on the shape of theobject occupying the passenger seat, in this case, the rear-facing childseat 342. Each object will reflect back waves having a differentpattern. Also, the pattern of waves received by transducer 344 willdiffer from the pattern received by transducer 346 in view of itsdifferent mounting location. This difference generally permits thedetermination of the location of the reflecting surface (i.e., therear-facing child seat 342) through triangulation. Through the use oftwo transducers 344,346, a sort of stereographic image is received bythe two transducers and recorded for analysis by processor 340, which iscoupled to the transducers 344,345,346. This image will differ for eachobject that is placed on the vehicle seat and it will also change foreach position of a particular object and for each position of thevehicle seat. Elements 344,345,346, although described as transducers,are representative of any type of component used in a wave-basedanalysis technique.

For ultrasonic systems, the “image” recorded from each ultrasonictransducer/receiver, is actually a time series of digitized data of theamplitude of the received signal versus time. Since there are tworeceivers, two time series are obtained which are processed by theprocessor 340. The processor 340 may include electronic circuitry andassociated, embedded software. Processor 340 constitutes one form of agenerating system in accordance with the invention which generatesinformation about the occupancy of the passenger compartment based onthe waves received by the transducers 344,345,346.

When different objects are placed on the front passenger seat, the twoimages from transducers 344,346, for example, are different but thereare also similarities between all images of rear-facing child seats, forexample, regardless of where on the vehicle seat they are placed andregardless of what company manufactured the child seat. Alternately,there will be similarities between all images of people sitting on theseat regardless of what they are wearing, their age or size. The problemis to find the “rules” which differentiate the images of one type ofobject from the images of other types of objects, e.g., whichdifferentiate the occupant images from the rear-facing child seatimages. The similarities of these images for various child seats arefrequently not obvious to a person looking at plots of the time seriesand thus computer algorithms are developed to sort out the variouspatterns. For a more detailed discussion of pattern recognition, seeU.S. Pat. No. 5,943,295.

The determination of these rules is important to the pattern recognitiontechniques used in this invention. In general, three approaches havebeen useful, artificial intelligence, fuzzy logic and artificial neuralnetworks (including cellular and modular or combination neural networksand support vector machines) (although additional types of patternrecognition techniques may also be used, such as sensor fusion). In someembodiments of this invention, such as the determination that there isan object in the path of a closing window as described below, the rulesare sufficiently obvious that a trained researcher can sometimes look atthe returned signals and devise an algorithm to make the requireddeterminations. In others, such as the determination of the presence ofa rear-facing child seat or of an occupant, artificial neural networksare used to determine the rules. One such set of neural network softwarefor determining the pattern recognition rules is available from theInternational Scientific Research, Inc. of Panama City, Panama and Kyiv,Ukraine.

The system used in a preferred implementation of inventions herein forthe determination of the presence of a rear-facing child seat, of anoccupant or of an empty seat is the artificial neural network. In thiscase, the network operates on the two returned signals as sensed bytransducers 344 and 346, for example. Through a training session, thesystem is taught to differentiate between the three cases. This is doneby conducting a large number of experiments where all possible childseats are placed in all possible orientations on the front passengerseat. Similarly, a sufficiently large number of experiments are run withhuman occupants and with boxes, bags of groceries and other objects(both inanimate and animate). Sometimes, as many as 1,000,000 suchexperiments are run before the neural network is sufficiently trained sothat it can differentiate among the three cases and output the correctdecision with a very high probability. Of course, it must be realizedthat a neural network can also be trained to differentiate amongadditional cases, e.g., a forward-facing child seat.

Once the network is determined, it is possible to examine the resultusing tools supplied International Scientific Research, for example, todetermine the rules that were finally arrived at by the trial and errortechniques. In that case, the rules can then be programmed into amicroprocessor resulting in a fuzzy logic or other rule-based system.Alternately, a neural computer, or cellular neural network, can be usedto implement the net directly. In either case, the implementation can becarried out by those skilled in the art of pattern recognition. If amicroprocessor is used, a memory device is also required to store thedata from the analog-to-digital converters that digitize the data fromthe receiving transducers. On the other hand, if a neural networkcomputer is used, the analog signal can be fed directly from thetransducers to the neural network input nodes and an intermediate memoryis not required. Memory of some type is needed to store the computerprograms in the case of the microprocessor system and if the neuralcomputer is used for more than one task, a memory is needed to store thenetwork specific values associated with each task.

Electromagnetic energy-based occupant sensors exist that use variousportions of the electromagnetic spectrum. A system based on theultraviolet, visible or infrared portions of the spectrum generallyoperate with a transmitter and a receiver of reflected radiation. Thereceiver may be a camera, focal plane array, or a photo detector such asa pin or avalanche diode as described in above-referenced patents andpatent applications. At other frequencies, the absorption of theelectromagnetic energy is primarily and at still other frequencies, thecapacitance or electric field influencing effects are used. Generally,the human body will reflect, scatter, absorb or transmit electromagneticenergy in various degrees depending on the frequency of theelectromagnetic waves. All such occupant sensors are included herein.

In the embodiment wherein electromagnetic energy is used, it is to beappreciated that any portion of the electromagnetic signals thatimpinges upon, surrounds or involves a body portion of the occupant isat least partially absorbed by the body portion. Sometimes, this is dueto the fact that the human body is composed primarily of water, and thatelectromagnetic energy of certain frequencies is readily absorbed bywater. The amount of electromagnetic signal absorption is related to thefrequency of the signal, and size or bulk of the body portion that thesignal impinges upon. For example, a torso of a human body tends toabsorb a greater percentage of electromagnetic energy than a hand of ahuman body.

Thus, when electromagnetic waves or energy signals are transmitted by atransmitter, the returning waves received by a receiver provide anindication of the absorption of the electromagnetic energy. That is,absorption of electromagnetic energy will vary depending on the presenceor absence of a human occupant, the occupant's size, bulk, surfacereflectivity, etc. depending on the frequency, so that different signalswill be received relating to the degree or extent of absorption by theoccupying item on the seat. The receiver will produce a signalrepresentative of the returned waves or energy signals which will thusconstitute an absorption signal as it corresponds to the absorption ofelectromagnetic energy by the occupying item in the seat.

One or more of the transducers 344,345,346 can also be image-receivingdevices, such as cameras, which take images of the interior of thepassenger compartment. These images can be transmitted to a remotefacility to monitor the passenger compartment or can be stored in amemory device for use in the event of an accident, i.e., to determinethe status of the occupants of the vehicle prior to the accident. Inthis manner, it can be ascertained whether the driver was fallingasleep, talking on the phone, etc.

To aid in the detection of the presence of child seats as well as theirorientation, a device 341 can be placed on the child seat in someconvenient location where its presence can be sensed by avehicle-mounted sensor that can be in the seat, dashboard, headliner orany other convenient location depending on the system design. The device341 can be a reflector, resonator, RFID tag, SAW device, or any othertag or similar device that permits easy detection of its presence andperhaps its location or proximity. Such a device can also be placed onany other component in the vehicle to indicate the presence, location oridentity of the component. For example, a vehicle may have a changeablecomponent where the properties of that component are used by anothersystem within the vehicle and thus the identification of the particularobject is needed so that the proper properties are used by the othersystem. An occupant monitoring system (e.g. ultrasonic, optical,electric field, etc.) may perform differently depending on whether theseat is made from cloth or leather or a weight sensor may depend on theproperties of a particular seat to provide the proper occupant weight.Thus, incorporation of an RFID, SAW, barcode or other tag or mark on anyobject that can be interrogated by an interrogator is contemplatedherein.

A memory device for storing the images of the passenger compartment, andalso for receiving and storing any of the other information, parametersand variables relating to the vehicle or occupancy of the vehicle, maybe in the form a standardized “black box” (instead of or in addition toa memory part in a processor 340). The IEEE Standards Association iscurrently beginning to develop an international standard for motorvehicle event data recorders. The information stored in the black boxand/or memory unit in the processor 340, can include the images of, orother information related to, the interior of the passenger compartmentas well as the number of occupants and the health state of theoccupants. The black box would preferably be tamper-proof andcrash-proof and enable retrieval of the information after a crash. Theuse of wave-type sensors as the transducers 344,345,346 as well aselectric field sensors is discussed above. Electric field sensors andwave sensors are essentially the same from the point of view of sensingthe presence of an occupant in a vehicle. In both cases, a time-varyingelectric field is disturbed or modified by the presence of the occupant.At high frequencies in the visual, infrared and high frequency radiowave region, the sensor is based on its capability to sense change ofwave characteristics of the electromagnetic field, such as amplitude,phase or frequency. As the frequency drops, other characteristics of thefield are measured. At still lower frequencies, the occupant'sdielectric properties modify parameters of the reactive electric fieldin the occupied space between/near the plates of a capacitor. In thislatter case, the sensor senses the change in charge distribution on thecapacitor plates by measuring, for example, the current wave magnitudeor phase in the electric circuit that drives the capacitor. Thesemeasured parameters are directly connected with parameters of thedisplacement current in the occupied space. In all cases, the presenceof the occupant reflects, absorbs or modifies the waves or variations inthe electric field in the space occupied by the occupant. Thus, for thepurposes of this invention, capacitance, electric field orelectromagnetic wave sensors are equivalent and although they are alltechnically “field” sensors they can be considered as “wave” sensorsherein. What follows is a discussion comparing the similarities anddifferences between two types of field or wave sensors, electromagneticwave sensors and capacitive sensors as exemplified by Kithil in U.S.Pat. No. 5,602,734 (see also U.S. Pat. No. 6,275,146, U.S. Pat. No.6,014,602, U.S. Pat. No. 5,844,486, U.S. Pat. No. 5,802,479, U.S. Pat.No. 5,691,693 and U.S. Pat. No. 5,366,241).

An electromagnetic field disturbed or emitted by a passenger in the caseof an electromagnetic wave sensor, for example, and the electric fieldsensor of Kithil, for example, are in many ways similar and equivalentfor the purposes of this invention. The electromagnetic wave sensor isan actual electromagnetic wave sensor by definition because it sensesparameters of a wave, which is a coupled pair of continuously changingelectric and magnetic fields. The electric field here is not a static,potential one. It is essentially a dynamic, rotational electric fieldcoupled with a changing magnetic one, that is, an electromagnetic wave.It cannot be produced by a steady distribution of electric charges. Itis initially produced by moving electric charges in a transmitter, evenif this transmitter is a passenger body for the case of a passiveinfrared sensor.

In the Kithil sensor, a static electric field is declared as an initialmaterial agent coupling a passenger and a sensor (see Column 5, lines5-7): “The proximity sensor 12 each function by creating anelectrostatic field between oscillator input loop 54 and detector outputloop 56, which is affected by presence of a person near by, as a resultof capacitive coupling, . . . ”. It is a potential, non-rotationalelectric field. It is not necessarily coupled with any magnetic field.It is the electric field of a capacitor. It can be produced with asteady distribution of electric charges. Thus, it is not anelectromagnetic wave by definition but if the sensor is driven by avarying current, then it produces a quasistatic electric field in thespace between/near the plates of the capacitor.

Kithil declares that his capacitance sensor uses a static electricfield. Thus, from the consideration above, one can conclude thatKithil's sensor cannot be treated as a wave sensor because there are noactual electromagnetic waves but only a static electric field of thecapacitor in the sensor system. However, this is not believed to be thecase. The Kithil system could not operate with a true static electricfield because a steady system does not carry any information. Therefore,Kithil is forced to use an oscillator, causing an alternate current inthe capacitor and a reactive quasi-static electric field in the spacebetween the capacitor plates, and a detector to reveal an informativechange of the sensor capacitance caused by the presence of an occupant(see FIG. 7 and its description in the '734 patent). In this case, thesystem becomes a “wave sensor” in the sense that it starts generatingactual time-varying electric field that certainly originateselectromagnetic waves according to the definition above. That is,Kithil's sensor can be treated as a wave sensor regardless of the shapeof the electric field that it creates a beam or a spread shape.

As follows from the Kithil patent, the capacitor sensor is likely aparametric system where the capacitance of the sensor is controlled bythe influence of the passenger body. This influence is transferred bymeans of the near electromagnetic field (i.e., the wave-like process)coupling the capacitor electrodes and the body. It is important to notethat the same influence takes place with a real static electric fieldalso, that is in absence of any wave phenomenon. This would be asituation if there were no oscillator in Kithil's system. However, sucha system is not workable and thus Kithil reverts to a dynamic systemusing time-varying electric fields.

Thus, although Kithil declares the coupling is due to a static electricfield, such a situation is not realized in his system because analternating electromagnetic field (“quasi-wave”) exists in the systemdue to the oscillator. Thus, the sensor is actually a wave sensor, thatis, it is sensitive to a change of a wave field in the vehiclecompartment. This change is measured by measuring the change of itscapacitance. The capacitance of the sensor system is determined by theconfiguration of its electrodes, one of which is a human body, that is,the passenger inside of and the part which controls the electrodeconfiguration and hence a sensor parameter, the capacitance.

The physics definition of “wave” from Webster's Encyclopedic UnabridgedDictionary is: “11. Physics. A progressive disturbance propagated frompoint to point in a medium or space without progress or advance of thepoints themselves, . . . ”. In a capacitor, the time that it takes forthe disturbance (a change in voltage) to propagate through space, thedielectric and to the opposite plate is generally small and neglectedbut it is not zero. As the frequency driving the capacitor increases andthe distance separating the plates increases, this transmission time asa percentage of the period of oscillation can become significant.Nevertheless, an observer between the plates will see the rise and fallof the electric field much like a person standing in the water of anocean in the presence of water waves. The presence of a dielectric bodybetween the plates causes the waves to get bigger as more electrons flowto and from the plates of the capacitor. Thus, an occupant affects themagnitude of these waves which is sensed by the capacitor circuit. Theelectromagnetic field is a material agent that carries information abouta passenger's position in both Kithil's and a beam-type electromagneticwave sensor.

Considering now a general occupant sensor and its connection to the restof the system, an alternate method as taught herein is to use aninterrogator to send a signal to the headliner-mounted ultrasonicsensor, for example, causing that sensor to transmit and receiveultrasonic waves. The sensor in this case could perform mathematicaloperations on the received waves and create a vector of data containingperhaps twenty to forty values and transmit that vector wirelessly tothe interrogator. By means of this system, the ultrasonic sensor needonly be connected to the vehicle power system and the information can betransferred to and from the sensor wirelessly (either by electromagneticor ultrasonic waves or equivalent). Such a system significantly reducesthe wiring complexity especially when there may be multiple such sensorsdistributed in the passenger compartment. Then, only a power wire needsto be attached to the sensor and there does not need to be any directconnection between the sensor and the control module. The samephilosophy applies to radar-based sensors, electromagnetic sensors ofall kinds including cameras, capacitive or other electromagnetic fieldchange sensitive sensors etc. In some cases, the sensor itself canoperate on power supplied by the interrogator through radio frequencytransmission. In this case, even the connection to the power line can beomitted. This principle can be extended to the large number of sensorsand actuators that are currently in the vehicle where the only wiresthat are needed are those to supply power to the sensors and actuatorsand the information is supplied wirelessly.

Such wireless powerless sensors can also be used, for example, as closeproximity sensors based on measurement of thermal radiation from anoccupant. Such sensors can be mounted on any of the surfaces in thepassenger compartment, including the seats, which are likely to receivesuch radiation.

A significant number of people are suffocated each year in automobilesdue to excessive heat, carbon dioxide, carbon monoxide, or otherdangerous fumes. The SAW sensor technology is particularly applicable tosolving these kinds of problems. The temperature measurementcapabilities of SAW transducers have been discussed above. If thesurface of a SAW device is covered with a material which captures carbondioxide, for example, such that the mass, elastic constants or otherproperty of surface coating changes, the characteristics of the surfaceacoustic waves can be modified as described in U.S. Pat. No. 4,637,987and elsewhere based on the carbon dioxide content of the air. Onceagain, an interrogator can sense the condition of these chemical-sensingsensors without the need to supply power. The interrogator can thereforecommunicate with the sensors wirelessly. If power is supplied then thiscommunication can be through the wires. If a concentration of carbonmonoxide is sensed, for example, an alarm can be sounded, the windowsopened, and/or the engine extinguished. Similarly, if the temperaturewithin the passenger compartment exceeds a certain level, the windowscan be automatically opened a little to permit an exchange of airreducing the inside temperature and thereby perhaps saving the life ofan infant or pet left in the vehicle unattended.

In a similar manner, the coating of the surface wave device can containa chemical which is responsive to the presence of alcohol. In this case,the vehicle can be prevented from operating when the concentration ofalcohol vapors in the vehicle exceeds some predetermined limit. Such adevice can advantageously be mounted in the headliner above the driver'sseat.

Each year, a number of children and animals are killed when they arelocked into a vehicle trunk. Since children and animals emit significantamounts of carbon dioxide, a carbon dioxide sensor connected to thevehicle system wirelessly and powerlessly provides an economic way ofdetecting the presence of a life form in the trunk. If a life form isdetected, then a control system can release a trunk lock thereby openingthe trunk. Alarms can also be sounded or activated when a life form isdetected in the trunk. An infrared or other sensor can perform a similarfunction.

FIG. 21 illustrates a SAW strain gage as described above, where thetension in the seat belt 350 can be measured without the requirement ofpower or signal wires. FIG. 21 illustrates a powerless and wirelesspassive SAW strain gage-based device 357 for this purpose. There aremany other places that such a device can be mounted to measure thetension in the seatbelt at one place or at multiple places.Additionally, a SAW-based accelerometer can be located on the seatbeltadjacent the chest of an occupant as a preferred measure of the stressplaced on the occupant by the seatbelt permitting that stress to becontrolled.

In FIG. 23, a bolt 360 is used to attach a vehicle seat to a supportstructure such as a slide mechanism as illustrated in FIGS. 21 and 22,among others, in U.S. Pat. No. 6,242,701. The bolt 360 is attached tothe seat or seat structure (not shown) by inserting threaded section 361containing threads 362 and then attaching a nut (not shown) to securethe bolt 360 to the seat or seat structure. Similarly, the lower sectionof the bolt 360 is secured to the slide mechanism (not shown) by lowerbolt portion 363 by means of a nut (not shown) engaging threads 364.Four such bolts 360 are typically used to attach the seat to thevehicle.

As the weight in the seat increases, the load is transferred to thevehicle floor by means of stresses in bolts 360. The stress in the boltsection 365 is not affect by stresses in the bolt sections 361 and 363caused by the engagement of the nuts that attach the bolts 360 to theseat and vehicle respectively.

The silicon strain gage 366 is attached, structured and arranged tomeasure the strain in bolt section 365 caused by loading from the seatand its contents. Silicon strain gage 366 is selected for its high gagefactor and low power requirements relative to other strain gagetechnologies. Associated electronics 367 are typically incorporated intoa single chip and may contain connections/couplings for wires, notshown, or radio frequency circuits and an antenna for radio frequencytransfer of power and signals from the strain gage 366 to aninterrogator mounted on the vehicle, not shown. In this manner, theinterrogator supplies power and receives the instantaneous strain valuethat is measured by the strain gage 366.

Although a single strain element 366 has been illustrated, the bolt 360may contain 1, 2, or even as many as 4 such strain gage assemblies onvarious sides of bolt section 365. Other stain gage technologies canalso be used.

Another example of a stud which is threaded on both ends and which canbe used to measure the weight of an occupant seat is illustrated inFIGS. 24A-24D. The operation of this device is disclosed in U.S. Pat.No. 6,653,577 wherein the center section of stud 371 is solid. It hasbeen discovered that sensitivity of the device can be significantlyimproved if a slotted member is used as described in U.S. Pat. No.5,539,236. FIG. 24A illustrates a SAW strain gage 372 mounted on asubstrate and attached to span a slot 374 in a center section 375 of thestud 371. This technique can be used with any other strain-measuringdevice.

FIG. 24B is a side view of the device of FIG. 24A.

FIG. 24C illustrates use of a single hole 376 drilled off-center in thecenter section 375 of the stud 371. The single hole 376 also serves tomagnify the strain as sensed by the strain gage 372. It has theadvantage in that strain gage 372 does not need to span an open space.The amount of magnification obtained from this design, however, issignificantly less than obtained with the design of FIG. 24A.

To improve the sensitivity of the device shown in FIG. 24C, multiplesmaller holes 377 can be used as illustrated in FIG. 24D. FIG. 24E in analternate configuration showing three of four gages 372 for determiningthe bending moments as well as the axial stress in the support member.

In operation, the SAW strain gage 372 receives radio frequency wavesfrom an interrogator 378 and returns electromagnetic waves via arespective antenna 373 which are delayed based on the strain sensed bystrain gage 372.

Occupant weight sensors can give erroneous results if the seatbelt ispulled tight pushing the occupant into the seat. This is particularly aproblem when the seatbelt is not attached to the seat. For such cases,it has been proposed to measure the tension in various parts of theseatbelt. Conventional technology requires that such devices behard-wired into the vehicle complicating the wire harness.

Other components of the vehicle can also be wirelessly coupled to theprocessor or central control module for the purposes of datatransmission and/or power transmission. A discussion of some componentsfollows.

Seat Systems

In more enhanced applications, it is envisioned that components of theseat will be integrated into the power transmission and communicationsystem. In many luxury cars, the seat subsystem is becoming verycomplicated. Seat manufacturers state that almost all warranty repairsare associated with the wiring and connectors associated with the seat.The reliability of seat systems can therefore be substantially improvedand the incidence of failures or warranty repairs drastically reduced ifthe wires and connectors can be eliminated from the seat subsystem.

Today, there are switches located on the seat or at other locations inthe vehicle for controlling the forward and backward motions, up anddown motions, and rotation of the seat and seat back. These switches areconnected to the appropriate motors by wires. Additionally, many seatsnow contain an airbag that must communicate with a sensor located, forexample, in the vehicle, B-pillar, sill or door. Many occupant presencesensors and weight sensing systems are also appearing on vehicle seats.Finally, some seats contain heaters and cooling elements, vibrators, andother comfort and convenience devices that require wires and switches.

As an example, let us now look at weight sensing. Under the teachings ofan invention disclosed herein, silicon strain gage weight sensors can beplaced on the bolts that secure each seat to the slide mechanism asshown in FIG. 23. These strain gage subsystems can contain sufficientelectronics and inductive pickup coils so as to receive theiroperational energy from a pair of wires appropriately placed beneath theseats. The seat weight measurements can then be superimposed on thepower frequency or transmitted wirelessly using RF or other convenientwireless technology. Other weight sensing technologies such as bladdersand pressure sensors or two-dimensional resistive deflection sensingmats can also be handled in a similar manner.

Other methods of seat weight sensing include measuring the deflection ofa part of the seat or the deflection of the bolts that connect the seatto the seat slide. For example, the strain in a bolt can be readilydetermined using, for example, SAW, wire or silicon strain gages,optical fiber strain gages, time of flight or phase of ultrasonic wavestraveling through the strained bolt, or the capacitive change of twoappropriately position capacitor plates.

Using the loosely coupled inductive system described above, power inexcess of a kilowatt can be readily transferred to operate seat positionmotors without the use of directly connected wires. The switches canalso be coupled into the inductive system without any direct wireconnections and the switches, which now can be placed on the doorarmrest or on the seat as desired, can provide the information tocontrol the seat motors. Additionally, since microprocessors will now bepresent on every motor and switch, the classical problem of the four-wayseat system to control three degrees of freedom can be easily solved.

In current four-way seat systems, when an attempt is made to verticallyraise the seat, the seat also rotates. Similarly, when an attempt ismade to rotate the seat, it also invariably moves either up or down.This is because there are four switches to control three degrees offreedom and thus there is an infinite combination of switch settings foreach seat position setting. This problem can be easily solved with analgorithm that translates the switch settings to the proper motorpositions. Thus only three switches are needed.

The positions of the seat, seatback and headrest, can also be readilymonitored without having direct wire connections to the vehicle. Thiscan be done in numerous ways beginning with the encoder system that iscurrently in use and ending with simple RFID radar reflective tags thatcan be interrogated by a remote RFID tag reader. Based on the time offlight of RF waves, the positions of all of the desired surfaces of theseat can be instantly determined wirelessly.

2.0 Telematics

2.1 Transmission of Vehicle and Occupant Information

Described herein is a system for determining the status of occupants ina vehicle, and/or of the vehicle, and in the event of an accident or atany other appropriate time, transmitting the status of the occupantsand/or the vehicle, and optionally additional information, via acommunications channel or link to a remote monitoring facility. Inaddition to the status of the occupant, it is also important to be ableto analyze the operating conditions of the vehicle and detect when acomponent of the vehicle is about to fail. By notifying the driver, adealer or other repair facility and/or the vehicle manufacturer of theimpending failure of the component, appropriate corrective action can betaken to avoid such failure.

As noted above, at least one invention herein relates generally totelematics and the transmission of information from a vehicle to one ormore remote sites which can react to the position or status of thevehicle or occupant(s) therein.

Initially, sensing of the occupancy of the vehicle and the optionaltransmission of this information, which may include images, to remotelocations will be discussed. This entails obtaining information fromvarious sensors about the occupant(s) in the passenger compartment ofthe vehicle, e.g., the number of occupants, their type and their motion,if any. Thereafter, general vehicle diagnostic methods will be discussedwith the diagnosis being transmittable via a communications device tothe remote locations. Finally, a discussion of various sensors for useon the vehicle to sense different operating parameters and conditions ofthe vehicle is provided. All of the sensors discussed herein can becoupled to a communications device enabling transmission of data,signals and/or images to the remote locations, and reception of the samefrom the remote locations.

FIG. 25 shows schematically the interface between a vehicle interiormonitoring system in accordance with the invention and the vehicle'scellular or other telematics communication system. An adult occupant 395is shown sitting on the front passenger seat 343 and four transducers344, 345, 347 and 348 are used to determine the presence (or absence) ofthe occupant on that seat 343. One of the transducers 345 in this caseacts as both a transmitter and receiver while transducer 344 can actonly as a receiver or as both a transmitter and receiver. Alternately,transducer 344 could serve as both a transmitter and receiver or thetransmitting function could be alternated between the two transducers344, 345. Also, in many cases more than two transmitters and receiversare used and in still other cases, other types of sensors, such aselectric field, capacitance, self-tuning antennas (collectivelyrepresented by 347 and 348), weight, seatbelt, heartbeat, motion andseat position sensors, are also used in combination with the radiationsensors.

For a general object, transducers 344, 345, 347, 348 can also be used todetermine the type of object, determine the location of the objectand/or determine another property or characteristic of the object. Aproperty of the object could be the presence and/or orientation of achild seat, the velocity of an adult and the like. For example, thetransducers 344, 345, 347, 348 can be designed to enable a determinationthat an object is present on the seat, that the object is a child seatand that the child seat is rear-facing.

The transducers 344 and 345 are attached to the vehicle buried in theA-pillar trim, where their presence can be disguised, and are connectedto processor 340 that may also be hidden in the trim as shown (thisbeing a non-limiting position for the processor 340). Other mountinglocations can also be used. For example, transducers 344, 345 can bemounted inside the seat (along with or in place of transducers 347 and348), in the ceiling of the vehicle, in the B-pillar, in the C-pillarand in the doors. Indeed, the vehicle interior monitoring system inaccordance with the invention may comprise a plurality of monitoringunits, each arranged to monitor a particular seating location. In thiscase, for the rear seating locations, transducers might be mounted inthe B-pillar or C-pillar or in the rear of the front seat or in the rearside doors. Possible mounting locations for transducers, transmitters,receivers and other occupant sensing devices are disclosed in theabove-referenced patents and patent applications and all of thesemounting locations are contemplated for use with the transducersdescribed herein.

The cellular phone or other communications system 396 outputs to anantenna 397. The transducers 344, 345, 347 and 348 in conjunction withthe pattern recognition hardware and software, which is implemented inprocessor 340 and is packaged on a printed circuit board or flex circuitalong with the transducers 344 and 345, determine the presence of anoccupant within a few seconds after the vehicle is started, or within afew seconds after the door is closed. Similar systems located to monitorthe remaining seats in the vehicle also determine the presence ofoccupants at the other seating locations and this result is stored inthe computer memory which is part of each monitoring system processor340.

Periodically and in particular in the event of or in anticipation of anaccident, the electronic system associated with the cellular phone orother telematics system 396 interrogates the various interior monitoringsystem memories and arrives at a count of the number of occupants in thevehicle, and optionally, even makes a determination as to whether eachoccupant was wearing a seatbelt and if he or she is moving after theaccident. The phone or other communications system then automaticallydials or otherwise contacts the EMS operator (such as 911 or through atelematics service such as OnStar®) and the information obtained fromthe interior monitoring systems is forwarded so that a determination canbe made as to the number of ambulances and other equipment to send tothe accident site, for example. Such vehicles will also have a system,such as the global positioning system, which permits the vehicle todetermine its exact location and to forward this information to the EMSoperator, for example.

An alternate preferred communications system is the use of satelliteinternet or Wi-Fi internet such is expected to be operational onvehicles in a few years. In this manner, the vehicle will always havecommunications access regardless of its location on the earth. This isbased on the premise that Wi-Fi will be in place for all those locationswhere satellite communication is not available such as in tunnels, urbancanyons and the like.

Thus, in basic embodiments of the invention, wave or otherenergy-receiving transducers are arranged in the vehicle at appropriatelocations, trained if necessary depending on the particular embodiment,and function to determine whether a life form is present in the vehicleand if so, how many life forms are present and where they are locatedetc. To this end, transducers can be arranged to be operative at only asingle seating locations or at multiple seating locations with aprovision being made to eliminate repetitive count of occupants. Adetermination can also be made using the transducers as to whether thelife forms are humans, or more specifically, adults, children in childseats, etc. As noted above, this is possible using pattern recognitiontechniques. Moreover, the processor or processors associated with thetransducers can be trained to determine the location of the life forms,either periodically or continuously or possibly only immediately before,during and after a crash. The location of the life forms can be asgeneral or as specific as necessary depending on the systemrequirements, i.e., that a human is situated on the driver's seat in anormal position (general) or a determination can be made that a human issituated on the driver's seat and is leaning forward and/or to the sideat a specific angle as well as the position of his or her extremitiesand head and chest (specifically). The degree of detail is limited byseveral factors, including, for example, the number, type and positionof transducers and training of the pattern recognition algorithm.

In addition to the use of transducers to determine the presence andlocation of occupants in a vehicle, other sensors could also be used.For example, a heartbeat sensor which determines the number and presenceof heartbeats can also be arranged in the vehicle, which would thus alsodetermine the number of occupants as the number of occupants would beequal to the number of heartbeats. Conventional heartbeat sensors can beadapted to differentiate between a heartbeat of an adult, a heartbeat ofa child and a heartbeat of an animal. As its name implies, a heartbeatsensor detects a heartbeat, and the magnitude thereof, of a humanoccupant of the seat, if such a human occupant is present. The output ofthe heartbeat sensor is input to the processor of the interiormonitoring system. One heartbeat sensor for use in the invention may beof the types as disclosed in McEwan (U.S. Pat. No. 5,573,012 and U.S.Pat. No. 5,766,208). The heartbeat sensor can be positioned at anyconvenient position relative to the seats where occupancy is beingmonitored. A preferred location is within the vehicle seat back.

An alternative way to determine the number of occupants is to monitorthe weight being applied to the seats, i.e., each seating location, byarranging weight sensors at each seating location which might also beable to provide a weight distribution of an object on the seat. Analysisof the weight and/or weight distribution by a predetermined method canprovide an indication of occupancy by a human, an adult or child, or aninanimate object.

Another type of sensor which is not believed to have been used in aninterior monitoring system heretofore is a micropower impulse radar(MIR) sensor which determines motion of an occupant and thus candetermine his or her heartbeat (as evidenced by motion of the chest).Such an MIR sensor can be arranged to detect motion in a particular areain which the occupant's chest would most likely be situated or could becoupled to an arrangement which determines the location of theoccupant's chest and then adjusts the operational field of the MIRsensor based on the determined location of the occupant's chest. Amotion sensor utilizing a micropower impulse radar (MIR) system isdisclosed, for example, in McEwan (U.S. Pat. No. 5,361,070), as well asmany other patents by the same inventor. Motion sensing is accomplishedby monitoring a particular range from the sensor, as disclosed in thatpatent. MIR is one form of radar which has applicability to occupantsensing and can be mounted at various locations in the vehicle. It hasan advantage over ultrasonic sensors in that data can be acquired at ahigher speed and thus the motion of an occupant can be more easilytracked. The ability to obtain returns over the entire occupancy rangeis somewhat more difficult than with ultrasound resulting in a moreexpensive system overall. MIR has additional advantages in lack ofsensitivity to temperature variation and has a comparable resolution toabout 40 kHz ultrasound. Resolution comparable to higher frequency isalso possible. Additionally, multiple MIR sensors can be used when highspeed tracking of the motion of an occupant during a crash is requiredsince they can be individually pulsed without interfering with eachthrough time division multiplexing.

An alternative way to determine motion of the occupant(s) is to monitorthe weight distribution of the occupant whereby changes in weightdistribution after an accident would be highly suggestive of movement ofthe occupant. A system for determining the weight distribution of theoccupants could be integrated or otherwise arranged in the right centerand left, front and back vehicle seats such as 343 and several patentsand publications describe such systems.

More generally, any sensor which determines the presence and healthstate of an occupant can also be integrated into the vehicle interiormonitoring system in accordance with the invention. For example, asensitive motion sensor can determine whether an occupant is breathingand a chemical sensor can determine the amount of carbon dioxide, or theconcentration of carbon dioxide, in the air in the vehicle which can becorrelated to the health state of the occupant(s). The motion sensor andchemical sensor can be designed to have a fixed operational fieldsituated where the occupant's mouth is most likely to be located. Inthis manner, detection of carbon dioxide in the fixed operational fieldcould be used as an indication of the presence of a human occupant inorder to enable the determination of the number of occupants in thevehicle. In the alternative, the motion sensor and chemical sensor canbe adjustable and adapted to adjust their operational field inconjunction with a determination by an occupant position and locationsensor which would determine the location of specific parts of theoccupant's body, e.g., his or her chest or mouth. Furthermore, anoccupant position and location sensor can be used to determine thelocation of the occupant's eyes and determine whether the occupant isconscious, i.e., whether his or her eyes are open or closed or moving.

The use of chemical sensors can also be used to detect whether there isblood present in the vehicle, for example, after an accident.Additionally, microphones can detect whether there is noise in thevehicle caused by groaning, yelling, etc., and transmit any such noisethrough the cellular or other communication connection to a remotelistening facility (such as operated by OnStar®).

FIG. 26 shows a schematic diagram of an embodiment of the inventionincluding a system for determining the presence and health state of anyoccupants of the vehicle and a telecommunications link. This embodimentincludes a system for determining the presence of any occupants 400which may take the form of a heartbeat sensor or motion sensor asdescribed above and a system for determining the health state of anyoccupants 401. The health state determining system may be integratedinto the system for determining the presence of any occupants, i.e., oneand the same component, or separate therefrom. Further, a system fordetermining the location, and optionally velocity, of the occupants orone or more parts thereof 402 are provided and may be any conventionaloccupant position sensor or preferably, one of the occupant positionsensors as described herein (e.g., those utilizing waves.electromagnetic radiation or electric fields) or as described in thecurrent assignee's patents and patent applications referenced above.

A processor 403 is coupled to the presence determining system 400, thehealth state determining system 401 and the location determining system402. A communications unit 404 is coupled to the processor 403. Theprocessor 403 and/or communications unit 404 can also be coupled tomicrophones 405 that can be distributed throughout the vehicle andinclude voice-processing circuitry to enable the occupant(s) to effectvocal control of the processor 403, communications unit 404 or anycoupled component or oral communications via the communications unit404. The processor 403 is also coupled to another vehicular system,component or subsystem 406 and can issue control commands to effectadjustment of the operating conditions of the system, component orsubsystem. Such a system, component or subsystem can be the heating orair-conditioning system, the entertainment system, an occupant restraintdevice such as an airbag, a glare prevention system, etc. Also, apositioning system 407 could be coupled to the processor 403 andprovides an indication of the absolute position of the vehicle,preferably using satellite-based positioning technology (e.g., a GPSreceiver).

In normal use (other than after a crash), the presence determiningsystem 400 determines whether any human occupants are present, i.e.,adults or children, and the location determining system 402 determinesthe occupant's location. The processor 403 receives signalsrepresentative of the presence of occupants and their location anddetermines whether the vehicular system, component or subsystem 406 canbe modified to optimize its operation for the specific arrangement ofoccupants. For example, if the processor 403 determines that only thefront seats in the vehicle are occupied, it could control the heatingsystem to provide heat only through vents situated to provide heat forthe front-seated occupants.

Another possible vehicular system, component or subsystem is anavigational aid, i.e., a route display or map. In this case, theposition of the vehicle as determined by the positioning system 407 isconveyed through processor 403 to the communications unit 404 to aremote facility and a map is transmitted from this facility to thevehicle to be displayed on the route display. If directions are needed,a request for the same could be entered into an input unit 408associated with the processor 403 and transmitted to the facility. Datafor the display map and/or vocal instructions could be transmitted fromthis facility to the vehicle.

Moreover, using this embodiment, it is possible to remotely monitor thehealth state of the occupants in the vehicle and most importantly, thedriver. The health state determining system 401 may be used to detectwhether the driver's breathing is erratic or indicative of a state inwhich the driver is dozing off. The health state determining system 401could also include a breath-analyzer to determine whether the driver'sbreath contains alcohol. In this case, the health state of the driver isrelayed through the processor 403 and the communications unit 404 to theremote facility and appropriate action can be taken. For example, itwould be possible to transmit a command (from the remote facility) tothe vehicle to activate an alarm or illuminate a warning light or if thevehicle is equipped with an automatic guidance system and ignitionshut-off, to cause the vehicle to come to a stop on the shoulder of theroadway or elsewhere out of the traffic stream. The alarm, warninglight, automatic guidance system and ignition shut-off are thusparticular vehicular components or subsystems represented by 406.

In use after a crash, the presence determining system 400, health statedetermining system 401 and location determining system 402 can obtainreadings from the passenger compartment and direct such readings to theprocessor 403. The processor 403 analyzes the information and directs orcontrols the transmission of the information about the occupant(s) to aremote, manned facility. Such information would include the number andtype of occupants, i.e., adults, children, infants, whether any of theoccupants have stopped breathing or are breathing erratically, whetherthe occupants are conscious (as evidenced by, e.g., eye motion), whetherblood is present (as detected by a chemical sensor) and whether theoccupants are making noise. Moreover, the communications link throughthe communications unit 404 can be activated immediately after the crashto enable personnel at the remote facility to initiate communicationswith the vehicle.

An occupant sensing system can also involve sensing for the presence ofa living occupant in a trunk of a vehicle or in a closed vehicle, forexample, when a child is inadvertently left in the vehicle or enters thetrunk and the trunk closes. To this end, a SAW-based chemical sensor 410is illustrated in FIG. 27A for mounting in a vehicle trunk asillustrated in FIG. 27. The chemical sensor 410 is designed to measurecarbon dioxide concentration through the mass loading effects asdescribed in U.S. Pat. No. 4,895,017 with a polymer coating selectedthat is sensitive to carbon dioxide. The speed of the surface acousticwave is a function of the carbon dioxide level in the atmosphere.Section 412 of the chemical sensor 410 contains a coating of such apolymer and the acoustic velocity in this section is a measure of thecarbon dioxide concentration. Temperature effects are eliminated througha comparison of the sonic velocities in sections 412 and 411 asdescribed above.

Thus, when the trunk lid 409 is closed and a source of carbon dioxidesuch as a child or animal is trapped within the trunk, the chemicalsensor 410 will provide information indicating the presence of thecarbon dioxide producing object to the interrogator which can thenrelease a trunk lock permitting the trunk lid 409 to automatically open.In this manner, the problem of children and animals suffocating inclosed trunks is eliminated. Alternately, information that a person oranimal is trapped in a trunk can be sent by the telematics system to lawenforcement authorities or other location or facility remote from thevehicle.

A similar device can be distributed at various locations within thepassenger compartment of vehicle along with a combined temperaturesensor. If the car has been left with a child or other animal whileowner is shopping, for example, and if the temperature rises within thevehicle to an unsafe level or, alternately, if the temperature dropsbelow an unsafe level, then the vehicle can be signaled to takeappropriate action which may involve opening the windows or starting thevehicle with either air conditioning or heating as appropriate.Alternately, information that a person or animal is trapped within avehicle can be sent by the telematics system to law enforcementauthorities or other location remote from the vehicle. Thus, throughthese simple wireless powerless sensors, the problem of suffocationeither from lack of oxygen or death from excessive heat or cold can allbe solved in a simple, low-cost manner through using an interrogator asdisclosed in U.S. Pat. No. 6,662,642.

Additionally, a sensitive layer on a SAW can be made to be sensitive toother chemicals such as water vapor for humidity control or alcohol fordrunk-driving control. Similarly, the sensitive layer can be designed tobe sensitive to carbon monoxide thereby preventing carbon monoxidepoisoning. Many other chemicals can be sensed for specific applicationssuch as to check for chemical leaks in commercial vehicles, for example.Whenever such a sensor system determines that a dangerous situation isdeveloping, an alarm can be sounded and/or the situation can beautomatically communicated to an off-vehicle location through theinternet, telematics, a cell phone such as a 911 call, the Internet orthough a subscriber service such as OnStar®.

The operating conditions of the vehicle can also be transmitted alongwith the status of the occupants to a remote monitoring facility. Theoperating conditions of the vehicle include whether the motor is runningand whether the vehicle is moving. Thus, in a general embodiment inwhich information on both occupancy of the vehicle and the operatingconditions of the vehicle are transmitted, one or more properties orcharacteristics of occupancy of the vehicle are determined, suchconstituting information about the occupancy of the vehicle, and one ormore states of the vehicle or of a component of the vehicle isdetermined, such constituting information about the operation of thevehicle. The information about the occupancy of the vehicle andoperation of the vehicle are selectively transmitted, possibly theinformation about occupancy to an emergency response center and theinformation about the vehicle to a dispatcher, a dealer or repairfacility and/or the vehicle manufacturer.

Transmission of the information about the operation of the vehicle,i.e., diagnostic information, may be achieved via a satellite and/or viathe Internet. The vehicle would thus include appropriate electronichardware and/or software to enable the transmission of a signal to asatellite, from where it could be re-transmitted to a remote location(for example via the Internet), and/or to enable the transmission to aweb site or host computer. In the latter case, the vehicle could beassigned a domain name or e-mail address for identification ortransmission origination purposes.

The diagnostic discussion above has centered on notifying the vehicleoperator of a pending problem with a vehicle component. Today, there isgreat competition in the automobile marketplace and the manufacturersand dealers who are most responsive to customers are likely to benefitby increased sales both from repeat purchasers and new customers. Thediagnostic module disclosed herein benefits the dealer by making himinstantly aware, through the cellular telephone system, or othercommunication link, coupled to the diagnostic module or system inaccordance with the invention, when a component is likely to fail. Asenvisioned when the diagnostic module 33 detects a potential failure itnot only notifies the driver through a display 34 (as shown in FIGS. 3and 4), but also automatically notifies the dealer through a vehiclecellular phone 32 or other telematics communication link such as theinternet via satellite or Wi-Fi. The dealer can thus contact the vehicleowner and schedule an appointment to undertake the necessary repair ateach party's mutual convenience. Contact by the dealer to the vehicleowner can occur as the owner is driving the vehicle, using acommunications device. Thus, the dealer can contact the driver andinform him of their mutual knowledge of the problem and discussscheduling maintenance to attend to the problem. The customer is pleasedsince a potential vehicle breakdown has been avoided and the dealer ispleased since he is likely to perform the repair work. The vehiclemanufacturer also benefits by early and accurate statistics on thefailure rate of vehicle components. This early warning system can reducethe cost of a potential recall for components having design defects. Itcould even have saved lives if such a system had been in place duringthe Firestone tire failure problem mentioned above. The vehiclemanufacturer will thus be guided toward producing higher qualityvehicles thus improving his competitiveness. Finally, experience withthis system will actually lead to a reduction in the number of sensorson the vehicle since only those sensors that are successful inpredicting failures will be necessary.

For most cases, it is sufficient to notify a driver that a component isabout to fail through a warning display. In some critical cases, actionbeyond warning the driver may be required. If, for example, thediagnostic module detected that the alternator was beginning to fail, inaddition to warning the driver of this eventuality, the diagnosticsystem could send a signal to another vehicle system to turn off allnon-essential devices which use electricity thereby conservingelectrical energy and maximizing the time and distance that the vehiclecan travel before exhausting the energy in the battery. Additionally,this system can be coupled to a system such as OnStar® or a vehicleroute guidance system, and the driver can be guided to the nearest openrepair facility or a facility of his or her choice.

FIG. 28 shows a schematic of the integration of the occupant sensingwith a telematics link and the vehicle diagnosis with a telematics link.As envisioned, the occupant sensing system 415 includes those componentswhich determine the presence, position, health state, and otherinformation relating to the occupants, for example the transducersdiscussed above with reference to FIGS. 20 and 21 and the SAW devicediscussed above with reference to FIG. 27. Information relating to theoccupants includes information as to what the driver is doing, talkingon the phone, communicating with OnStar®, the internet or other routeguidance, listening to the radio, sleeping, drunk, drugged, having aheart attack, etc. The occupant sensing system may also be any of thosesystems and apparatus described in any of the current assignee'sabove-referenced patents and patent applications or any other comparableoccupant sensing system which performs any or all of the same functionsas they relate to occupant sensing. Examples of sensors which might beinstalled on a vehicle and constitute the occupant sensing systeminclude heartbeat sensors, motion sensors, weight sensors, ultrasonicsensors, MIR sensors, microphones and optical sensors.

A crash sensor 416 is provided and determines when the vehicleexperiences a crash. Crash sensor 416 may be any type of crash sensor.

Vehicle sensors 417 include sensors which detect the operatingconditions of the vehicle such as those sensors discussed with referenceto FIG. 27 and others above. Also included are tire sensors such asdisclosed in U.S. Pat. No. 6,662,642. Other examples include velocityand acceleration sensors, and angular and angular rate pitch, roll andyaw sensors or an IMU. Of particular importance are sensors that tellwhat the car is doing: speed, skidding, sliding, location, communicatingwith other cars or the infrastructure, etc.

Environment sensors 418 include sensors which provide data concerningthe operating environment of the vehicle, e.g., the inside and outsidetemperatures, the time of day, the location of the sun and lights, thelocations of other vehicles, rain, snow, sleet, visibility (fog),general road condition information, pot holes, ice, snow cover, roadvisibility, assessment of traffic, video pictures of an accident eitherinvolving the vehicle or another vehicle, etc. Possible sensors includeoptical sensors which obtain images of the environment surrounding thevehicle, blind spot detectors which provide data on the blind spot ofthe driver, automatic cruise control sensors that can provide images ofvehicles in front of the host vehicle, and various radar and lidardevices which provide the position of other vehicles and objectsrelative to the subject vehicle.

The occupant sensing system 415, crash sensors 416, vehicle sensors 417,and environment sensors 418 can all be coupled to a communicationsdevice 419 which may contain a memory unit and appropriate electricalhardware to communicate with all of the sensors, process data from thesensors, and transmit data from the sensors. The memory unit could beuseful to store data from the sensors, updated periodically, so thatsuch information could be transmitted at set time intervals.

The communications device 419 can be designed to transmit information toany number of different types of facilities. For example, thecommunications device 419 could be designed to transmit information toan emergency response facility 420 in the event of an accident involvingthe vehicle. The transmission of the information could be triggered by asignal from the crash sensor 416 that the vehicle was experiencing acrash or had experienced a crash. The information transmitted could comefrom the occupant sensing system 415 so that the emergency responsecould be tailored to the status of the occupants. For example, if thevehicle was determined to have ten occupants, more ambulances might besent than if the vehicle contained only a single occupant. Also, if theoccupants are determined not be breathing, then a higher priority callwith living survivors might receive assistance first. As such, theinformation from the occupant sensing system 415 could be used toprioritize the duties of the emergency response personnel.

Information from the vehicle sensors 417 and environment sensors 418could also be transmitted to law enforcement authorities 422 in theevent of an accident so that the cause(s) of the accident could bedetermined. Such information can also include information from theoccupant sensing system 415, which might reveal that the driver wastalking on the phone, putting on make-up, or another distractingactivity, information from the vehicle sensors 417 which might reveal aproblem with the vehicle, and information from the environment sensors418 which might reveal the existence of slippery roads, dense fog andthe like.

Information from the occupant sensing system 415, vehicle sensors 417and environment sensors 418 could also be transmitted to the vehiclemanufacturer 423 in the event of an accident so that a determination canbe made as to whether failure of a component of the vehicle caused orcontributed to the cause of the accident. For example, the vehiclesensors might determine that the tire pressure was too low so thatadvice can be disseminated to avoid maintaining the tire pressure toolow in order to avoid an accident. Information from the vehicle sensors417 relating to component failure could be transmitted to adealer/repair facility 421 which could schedule maintenance to correctthe problem.

The communications device 419 could be designed to transmit particularinformation to each site, i.e., only information important to beconsidered by the personnel at that site. For example, the emergencyresponse personnel have no need for the fact that the tire pressure wastoo low but such information is important to the law enforcementauthorities 422 (for the possible purpose of issuing a recall of thetire and/or vehicle) and the vehicle manufacturer 423.

The communication device can be a cellular phone, DSRC, OnStar®, orother subscriber-based telematics system, a peer-to-peer vehiclecommunication system that eventually communicates to the infrastructureand then, perhaps, to the Internet with e-mail or instant message to thedealer, manufacturer, vehicle owner, law enforcement authorities orothers. It can also be a vehicle to LEO or Geostationary satellitesystem such as SkyBitz which can then forward the information to theappropriate facility either directly or through the Internet or a directconnection to the internet through a satellite or 802.11 Wi-Fi link orequivalent.

The communication may need to be secret so as not to violate the privacyof the occupants and thus encrypted communication may, in many cases, berequired. Other innovations described herein include the transmission ofany video data from a vehicle to another vehicle or to a facility remotefrom the vehicle by any means such as a telematics communication systemsuch as DSRC, OnStar®, a cellular phone system, a communication via GEO,geocentric or other satellite system and any communication thatcommunicates the results of a pattern recognition system analysis. Also,any communication from a vehicle can combine sensor information withlocation information.

When optical sensors are provided as part of the occupant sensing system415, video conferencing becomes a possibility, whether or not thevehicle experiences a crash. That is, the occupants of the vehicle canengage in a video conference with people at another location 424 viaestablishment of a communications channel by the communications device419.

The vehicle diagnostic system described above using a telematics linkcan transmit information from any type of sensors on the vehicle.

In one particular use of the invention, a wireless sensing andcommunication system is provided whereby the information or dataobtained through processing of input from sensors of the wirelesssensing and communication system is further transmitted for reception bya remote facility. Thus, in such a construction, there is anintra-vehicle communications between the sensors on the vehicle and aprocessing system (control module, computer or the like) and remotecommunications between the same or a coupled processing system (controlmodule, computer or the like). The electronic components for theintra-vehicle communication may be designed to transmit and receivesignals over short distances whereas the electronic components whichenable remote communications should be designed to transmit and receivesignals over relatively long distances.

The wireless sensing and communication system includes sensors that arelocated on the vehicle or in the vicinity of the vehicle and whichprovide information which is transmitted to one or more interrogators inthe vehicle by wireless radio frequency means, using wireless radiofrequency transmission technology. In some cases, the power to operate aparticular sensor is supplied by the interrogator while in other cases,the sensor is independently connected to either a battery, generator(piezo electric, solar etc.), vehicle power source or some source ofpower external to the vehicle.

One particular system requires mentioning which is the use of high speedsatellite or Wi-Fi internet service such as supplied by Wi-Fi hot spotsor KVH Industries, Inc. for any and all vehicle communications includingvehicle telephone, TV and radio services. With thousands of radiostations available over the internet, for example (see shoutcast.com), ahigh speed internet connection is clearly superior to satellite radiosystems that are now being marketed. Similarly, with ubiquitous internetaccess that KVH supplies throughout the country, the lack of coverageproblems with cell phones disappears. This capability becomesparticularly useful for emergency notification when a vehicle has anaccident or becomes disabled.

3.0 Wiring and Busses

In the discussion above, the diagnostic module of this invention assumesthat a vehicle data bus exists which is used by all of the relevantsensors on the vehicle. Most vehicles today do not have a data busalthough it is widely believed that most vehicles will have one in thefuture. In lieu of such a bus, the relevant signals can be transmittedto the diagnostic module through a variety of coupling systems otherthan through a data bus and this invention is not limited to vehicleshaving a data bus. For example, the data can be sent wirelessly to thediagnostic module using the Bluetooth™, ZIGBEE or 802.11 or similarspecification. In some cases, even the sensors do not have to be wiredand can obtain their power via RF from the interrogator as is well knownin the RFID radio frequency identification field (either silicon orsurface acoustic wave (SAW)-based)). Alternately, an inductive orcapacitive power transfer system can be used.

Several technologies have been described above all of which have theobjective of improving the reliability and reducing the complexity ofthe wiring system in an automobile and particularly the safety system.Most importantly, the bus technology described has as its objectivesimplification and increase in reliability of the vehicle wiring system.The safety system wiring was first conceived of as a method forpermitting the location of airbag crash sensors at locations where theycan most effectively sense a vehicle crash and yet permit thatinformation to be transmitted to the airbag control circuitry which maybe located in a protected portion of the interior of the vehicle or mayeven be located on the airbag module itself. Protecting thistransmission requires a wiring system that is far more reliable andresistant to being destroyed in the very crash that the sensor issensing. This led to the realization that the data bus that carries theinformation from the crash sensor must be particularly reliable. Upondesigning such a data bus, however, it was found that the capacity ofthat data bus far exceeded the needs of the crash sensor system. Thisthen led to a realization that the capacity, or bandwidth, of such a buswould be sufficient to carry all of the vehicle informationrequirements. In some cases, this requires the use of high bandwidth bustechnology such as twisted pair wires, shielded twisted pair wires, orcoax cable. If a subset of all of the vehicle devices is included on thebus, then the bandwidth requirements are less and simpler bustechnologies can be used instead of a coax cable, for example. Theeconomics that accompany a data bus design which has the highestreliability, highest bandwidth, is justified if all of the vehicledevices use the same system. This is where the greatest economies andgreatest reliability occur. As described above, this permits, forexample, the placement of the airbag firing electronics into or adjacentthe housing that contains the airbag inflator. Once the integrity of thedata bus is assured, such that it will not be destroyed during the crashitself, then the proper place for the airbag intelligence can be in, oradjacent to, the airbag module itself. This further improves thereliability of the system since the shorting of the wires to the airbagmodule will not inadvertently set off the airbag as has happenedfrequently in the past.

When operating on the vehicle data bus, each device should have a uniqueaddress. For most situations, therefore, this address must bepredetermined and then assigned through an agreed-upon standard for allvehicles. Thus, the left rear tail light must have a unique address sothat when the turn signal is turned to flash that light, it does notalso flash the right tail light, for example. Similarly, the side impactcrash sensor which will operate on the same data bus as the frontalimpact crash sensor, must issue a command, directly or indirectly, tothe side impact airbag and not to the frontal impact airbag.

One of the key advantages of a single bus system connecting all sensorsin the vehicle together is the possibility of using this data bus todiagnose the health of the entire safety system or of the entirevehicle, as described above. Thus, there are clear synergisticadvantages to all the disparate technologies described above.

The design, construction, installation, and maintenance a vehicle databus network requires attention to many issues, including: an appropriatecommunication protocol, physical layer transceivers for the selectedmedia, capable microprocessors for application and protocol execution,device controller hardware and software for the required sensors andactuators, etc. Such activities are known to those skilled in the artand will not be described herein.

An intelligent distributed system as described above can be based on theCAN Protocol, for example, which is a common protocol used in theautomotive industry. CAN is a full function network protocol thatprovides both message checking and correction to insure communicationintegrity. Many of the devices on the system will have their own specialdiagnostics. For instance, an inflator control system can send a warningmessage if its backup power supply has insufficient charge. In order toassure the integrity and reliability of the bus system, most deviceswill be equipped with bidirectional communication as described above.Thus, when a message is sent to the rear right taillight to turn on, thelight can return a message that it has executed the instruction.

In a refinement of this embodiment, more of the electronics associatedwith the airbag system can be decentralized and housed within or closelyadjacent to each of the airbag modules. Each module can have its ownelectronic package containing a power supply and diagnostic andsometimes also the occupant sensor electronics. One sensor system isstill used to initiate deployment of all airbags associated with thefrontal impact. To avoid the noise effects of all airbags deploying atthe same time, each module sometimes has its own delay. The modules forthe rear seat, for example, can have a several millisecond firing delaycompared with the module for the driver and the front passenger modulecan have a lesser delay. Each of the modules can also have its ownoccupant position sensor and associated electronics. In thisconfiguration, there is a minimum reliance on the transmission of powerand data to and from the vehicle electrical system which is the leastreliable part of the airbag system, especially during a crash. Once eachof the modules receives a signal from the crash sensor system, it is onits own and no longer needs either power or information from the otherparts of the system. The main diagnostics for a module can also residewithin the module which transmits either a ready or a fault signal tothe main monitoring circuit which now needs only to turn on a warninglight, and perhaps record the fault, if any of the modules either failsto transmit a ready signal or sends a fault signal.

Thus, the placement of electronic components in or near (proximate oradjacent) the airbag module can be important for safety and reliabilityreasons. The placement of the occupant sensing as well as thediagnostics electronics within or adjacent to the airbag module hasadditional advantages to solving several current important airbagproblems. For example, there have been numerous inadvertent airbagdeployments caused by wires in the system becoming shorted. Then, whenthe vehicle hits a pothole, which is sufficient to activate an armingsensor or otherwise disturb the sensing system, the airbag can deploy.Such an unwanted deployment of course can directly injure an occupantwho is out-of-position or cause an accident resulting in occupantinjuries. If the sensor were to send a coded signal to the airbag modulerather than a DC voltage with sufficient power to trigger the airbag,and if the airbag module had stored within its electronic circuitsufficient energy to initiate the inflator, then these unwanteddeployments could be prevented. A shorted wire cannot send a codedsignal and the short can be detected by the module resident diagnosticcircuitry.

This would require that the airbag module contain, or have adjacent orproximate to it, a power supply (formerly the backup power supply) whichfurther improves the reliability of the system since the electricalconnection to the sensor, or to the vehicle power, can now partiallyfail, as might happen during an accident, and the system will still workproperly. It is well known that the electrical resistance in the“clockspring” connection system, which connects the steeringwheel-mounted airbag module to the sensor and diagnostic system, hasbeen marginal in design and prone to failure. The resistance of thiselectrical connection must be very low or there will not be sufficientpower to reliably initiate the inflator squib. To reduce the resistanceto the level required, high quality gold-plated connectors arepreferably used and the wires should also be of unusually high quality.Due to space constraints, however, these wires frequently have only amarginally adequate resistance thereby reducing the reliability of thedriver airbag module and increasing its cost. If, on the other hand, thepower to initiate the airbag were already in the module, then only acoded signal needs to be sent to the module rather than sufficient powerto initiate the inflator. Thus, the resistance problem disappears andthe module reliability is increased. Additionally, the requirements forthe clockspring wires become less severe and the design can be relaxedreducing the cost and complexity of the device. It may even be possibleto return to the slip ring system that existed prior to theimplementation of airbags.

Under this system, the power supply can be charged over a few seconds,since the power does not need to be sent to the module at the time ofthe required airbag deployment because it is already there. Thus, all ofthe electronics associated with the airbag system except the sensor andits associated electronics, if any, could be within or adjacent to theairbag module. This includes optionally the occupant sensor, thediagnostics and the (backup) power supply, which now becomes the primarypower supply, and the need for a backup disappears. When a fault isdetected, a message is sent to a display unit located typically in theinstrument panel.

The placement of the main electronics within each module follows thedevelopment path that computers themselves have followed from a largecentralized mainframe base to a network of microcomputers. The computingpower required by an occupant position sensor, airbag system diagnosticsand backup power supply can be greater than that required by a singlepoint sensor or of a sensor system employing satellite sensors. For thisreason, it can be more logical to put this electronic package within oradjacent to each module. In this manner, the advantages of a centralizedsingle point sensor and diagnostic system fade since most of theintelligence will reside within or adjacent to the individual modulesand not the centralized system. A simple and more effective CrushSwitchsensor such as disclosed in U.S. Pat. No. 5,441,301, for example, nowbecomes more cost effective than the single point sensor and diagnosticsystem which is now being widely adopted. Finally, this also isconsistent with the migration to a bus system where the power andinformation are transmitted around the vehicle on a single bus systemthereby significantly reducing the number of wires and the complexity ofthe vehicle wiring system. The decision to deploy an airbag is sent tothe airbag module sub-system as a signal not as a burst of power.Although it has been assumed that the information would be sent over awire bus, it is also possible to send the deploy command by a variety ofwireless methods either using wires or wirelessly.

A partial implementation of the system as just described is depictedschematically in FIG. 29 which shows a view of the combination of anoccupant position sensor and airbag module designed to prevent thedeployment of the airbag for a seat which is unoccupied or if theoccupant is too close to the airbag and therefore in danger ofdeployment-induced injury. The module, shown generally at 430, includesa housing which comprises an airbag 431, an inflator assembly 432 forthe airbag 431, an occupant position sensor comprising an ultrasonictransmitter 433 and an ultrasonic receiver 434. Other occupant positionsensors can also be used instead of the ultrasonic transmitter/receiverpair to determine the position of the occupant to be protected by theairbag 431, and also the occupant position sensor (433,434) may belocated outside of the housing of the module 430. A preferredalternative occupant sensor system uses a camera as disclosed in severalof the assignee's patents such as U.S. Pat. No. 5,748,473, U.S. Pat. No.5,835,613, U.S. Pat. No. 6,141,432, U.S. Pat. No. 6,270,116, U.S. Pat.No. 6,324,453 and U.S. Pat. No. 6,856,873. In the ultrasonic example,the housing of the module 430 also can contain an electronic module orpackage 435 coupled to each of the inflator assembly 432, thetransmitter 433 and the receiver 434 and which performs the functions ofsending the ultrasonic signal to the transmitter 433 and processing thedata from the occupant position sensor receiver 434. Electronics module435 may be arranged within the housing of the module 430 as shown oradjacent or proximate the housing of the module 430. Module 430 can alsocontain a power supply (not shown) for supplying power upon command bythe electronics module 435 to the inflator assembly 432 to causeinflation of the airbag 431. Thus, electronics module 435 controls theinflation or deployment of the airbag 431 and may sometimes herein bereferred to as a controller or control unit. In addition, the electronicmodule 435 can monitor the power supply voltage, to assure thatsufficient energy is stored to initiate the inflator assembly 432 whenrequired, and power the other processes, and can report periodicallyover the vehicle bus 436 to the central diagnostic module, shownschematically at 437, to indicate that the module is ready, i.e., thereis sufficient power of inflate or deploy the airbag 431 and operate theoccupant position sensor transmitter/receiver pair 433, 434, or sends afault code if a failure in any component being monitored has beendetected. A CrushSwitch sensor is also shown schematically at 438, whichcan be the only discriminating sensor in the system. Sensor 438 iscoupled to the vehicle bus 436 and can transmit a coded signal over thebus to the electronics module 435 to cause the electronics module 435 toinitiate deployment of the airbag 431 via the inflator assembly 432. Thevehicle bus 436 connects the electronic package 435, the central sensorand diagnostic module 437 and the CrushSwitch sensor 438. Bus 436 may bethe single bus system, i.e., consists of a pair of wires, on which powerand information are transmitted around the vehicle as noted immediatelyabove. Instead of CrushSwitch sensor 438, other crash sensors may beused.

When several crash sensors and airbag modules are present in thevehicle, they can all be coupled to the same bus or discrete portions ofthe airbag modules and crash sensors can be coupled to separate buses.Other ways for connecting the crash sensors and airbag modules to anelectrical bus can also be implemented in accordance with the inventionsuch as connecting some of the sensors and/or modules in parallel to abus and others daisy-chained onto the bus. This type of bus architectureis described in U.S. Pat. No. 6,212,457.

It should be understood that airbag module 430 is a schematicrepresentation only and thus, may represent any of the airbag modulesdescribed above in any of the mounting locations. For example, airbagmodule 430 may be arranged in connection with the seat 525 as module 510is in FIG. 30, as a side curtain airbag or as a passenger side airbag orelsewhere. For the seat example, the bus, which is connected to theairbag module 510, would inherently extend at least partially into andwithin the seat.

Another implementation of the invention incorporating the electroniccomponents into and adjacent to the airbag module as illustrated in FIG.31 which shows the interior front of the passenger compartment generallyat 445. Driver airbag module 446 is partially cutaway to show anelectronic module 447 incorporated within the airbag module 446.Electronic module 447 may be comparable to electronic module 435 in theembodiment of FIG. 29 in that it can control the deployment of theairbag in airbag module 446. Electronic airbag module 446 is connectedto an electronic sensor illustrated generally as 451 by a wire 448. Theelectronic sensor 451 can be, for example, an electronic single pointcrash sensor that initiates the deployment of the airbag when it sensesa crash. Passenger airbag module 450 is illustrated with its associatedelectronic module 452 outside of but adjacent or proximate to the airbagmodule. Electronic module 452 may be comparable to electronic module 439in the embodiment of FIG. 29 in that it can control the deployment ofthe airbag in airbag module 450. Electronic module 452 is connected by awire 449, which could also be part of a bus, to the electronic sensor 451. One or both of the electronic modules 447 and 452 can containdiagnostic circuitry, power storage capability (either a battery or acapacitor), occupant sensing circuitry, as well as communicationelectronic circuitry for either wired or wireless communication.

It should be understood that although only two airbag modules 446,450are shown, it is envisioned that an automotive safety network may bedesigned with several and/or different types of occupant protectiondevices. Such an automotive network can comprise one or more occupantprotection devices connected to the bus, each comprising a housing and acomponent deployable to provide protection for the occupant, at leastone sensor system for providing an output signal relevant to deploymentof the deployable component(s) (such as the occupant sensing circuitry),a deployment determining system for generating a signal indicating forwhich of the deployable components deployment is desired (such as acrash sensor) and an electronic controller arranged in, proximate oradjacent each housing and coupled to the sensor system(s) and thedeployment determining system. The electrical bus electrically couplesthe sensor system(s), the deployment determining system and thecontrollers so that the signals from one or more of the sensor systemsand the deployment determining system are sent over the bus to thecontrollers. Each controller controls deployment of the deployablecomponent of the respective occupant protection device in considerationof the signals from the sensor system(s) and the deployment determiningsystem. The crash sensor(s) may be arranged separate and at a locationapart from the housings and generate a coded signal when deployment ofany one of the deployable components is desired. Thus, the coded signalvaries depending on which of deployment components are to be deployed.If the deployable component is an airbag associated with the housing,the occupant protection device would comprise an inflator assemblyarranged in the housing for inflating the airbag.

The safety bus, or any other vehicle bus, may use a coaxial cable. Aconnector for joining two coaxial cables 457 and 458 is illustrated inFIGS. 22A, 22B, 22C and 22D generally at 455. A cover 456 can be hingabbase 459. A connector plate 461 can be slidably inserted into base 459and can contain two abrasion and connection sections 463 and 464. Asecond connecting plate 465 can contain two connecting pins 462, onecorresponding to each cable to be connected. To connect the two cables457 and 458 together is this implementation, they are first insertedinto their respective holes 466 and 467 in base 459 until they areengaged by pins 462. Sliding connector plate 461 is inserted and cover460 rotated pushing connector plate 461 downward until the catch 468snaps over mating catch 469. Other latching devices are of course usablein accordance with the invention. During this process, the serrated part463 of connector plate 461 abrades the insulating cover off of theoutside of the respective cable exposing the outer conductor. Theparticle coated section 464 of connector plate 461 then engages andmakes electrical contact with the outer conductor of the coaxial cables457 and 458. In this manner, the two coaxial cables 457,458 areelectrically connected together in a very simple manner.

Consider now various uses of a bus system.

3.1 Airbag Systems

The airbag system currently involves a large number of wires that carryinformation and power to and from the airbag central processing unit.Some vehicles have sensors mounted in the front of the vehicle and manyvehicles also have sensors mounted in the side structure (the door,B-Pillar, sill, or any other location that is rigidly connected to theside crush zone of the vehicle). In addition, there are sensors and anelectronic control module mounted in the passenger compartment. All carsnow have passenger and driver airbags and some vehicles have as many aseight airbags considering the side impact torso airbag and head airbagsas well as knee bolster airbags.

To partially cope with this problem, there is a movement to connect allof the safety systems onto a single bus (see for example U.S. Pat. No.6,326,704). Once again, the biggest problem with the reliability ofairbag systems is the wiring and connectors. By practicing the teachingsof this invention, one single pair of wires can be used to connect allof the airbag sensors and airbags together and, in one preferredimplementation, to do so without the use of connectors. Thus, thereliability of the system is substantially improved and the reducedinstallation costs more than offsets the added cost of having a looselycoupled inductive network, for example, described elsewhere herein.

With such a system, more and more of the airbag electronics can residewithin or adjacent to the airbag module with the crash sensor andoccupant information fed to the electronics modules for the deploydecision. Thus, all of the relevant information can reside on thevehicle safety or general bus with each airbag module making its owndeploy decision locally.

3.2 Steering Wheel

The steering wheel of an automobile is becoming more complex as morefunctions are incorporated utilizing switches and/or a touch pad, forexample, on the steering wheel or other haptic or non-haptic input oreven output devices. Many vehicles have controls for heating and airconditioning, cruise control, radio, etc.

Although previously not implemented, a steering can also be an outputdevice by causing various locations on the steering wheel to provide avibration, electrical shock or other output to the driver. This is incontrast to vibrating the entire steering wheel which has been proposedfor an artificial rumble strip application when a vehicle departs fromits lane. Such a local feedback can be used to identify for the driverwhich button he or she should press to complete an action such asdialing a phone number, for example (see H Kajimoto et al., SmartTouch:Electric Skin to Touch the Untouchable” IEEE Computer Graphics andApplications, pp 36-43, January-February, 2004, IEEE).

Additionally, the airbag must have a very high quality connection sothat it reliably deploys even when an accident is underway.

This has resulted in the use of clockspring ribbon cables that make allof the electrical connections between the vehicle and the rotatingsteering wheel. The ribbon cable must at least able to carry sufficientcurrent to reliably initiate airbag deployment even at very coldtemperatures. This requires that the ribbon cable contain at least twoheavy conductors to bring power to the airbag. Under the airbag networkconcept, a capacitor or battery can be used within the airbag module andkept charged thereby significantly reducing the amount of current thatmust pass through the ribbon cable. Thus, the ribbon cable can be keptconsiderably smaller, as discussed above.

An alternate and preferred solution uses the teachings of this inventionto inductively couple the steering wheel with the vehicle thuseliminating all wires and connectors. All of the switch functions,control functions, and airbag functions are multiplexed on top of theinductive carrier frequency. This greatly simplifies the initialinstallation of the steering wheel onto the vehicle since a complicatedribbon cable is no longer necessary. Similarly, it reduces warrantyrepairs caused by people changing steering wheels without making surethat the ribbon cable is properly positioned.

As described elsewhere herein, an input device such as a mouse pad, joystick or even one or more switches can be placed on the steering wheeland used to control a display such as a heads-up display thus permittingthe vehicle operator to control many functions of a vehicle withouttaking his or her eyes off of the road. BMW recently introduced the IPODhaptic interface which attempts to permit the driver to control manyvehicle functions (HVAC, etc.) but it lacks the display feedback andthus has been found confusing to vehicle operators. This problemdisappears when such a device is coupled with a display and particularlya heads-up display as taught herein. Although a preferred location forthe input device is the steering wheel, it can be placed at otherlocations in the vehicle as is the IPOD.

The use of a haptic device can be extended to give feedback to theoperator. If the phone rings, for example, a particular portion of thesteering wheel can be made to vibrate indicating where the operatorshould depress a switch to answer the phone. The display can alsoindicate to the driver that the phone is ringing and perhaps indicate tohim or her the location of the switch or that a oral command should begiven to answer the phone.

An example of the implementation of this concept is described withreference to FIGS. 71A-72 of the parent '288 application.

3.3 Door Subsystem

More and more electrical functions are also being placed into vehicledoors. This includes window control switches and motors as well as seatcontrol switches, airbag crash sensors, etc. As a result the bundle ofwires that must pass through the door edge and through the A-pillar hasbecome a serious assembly and maintenance problem in the automotiveindustry. Using the teachings of this invention, a loosely coupledinductive system could pass anywhere near the door and an inductivepickup system placed on the other side where it obtains power andexchanges information when the mating surfaces are aligned. If thesesurfaces are placed in the A-pillar, then sufficient power can beavailable even when the door is open. Alternately, a battery orcapacitive storage system can be provided in the door and the couplingcan exist through the doorsill, for example. This eliminates the needfor wires to pass through the door interface and greatly simplifies theassembly and installation of doors. It also greatly reduces warrantyrepairs caused by the constant movement of wires at the door and carbody interface.

3.4 Blind Spot Monitor

Many accidents are caused by a driver executing a lane change when thereis another vehicle in his blind spot. As a result, several firms aredeveloping blind spot monitors based on radar, optics, or passiveinfrared, to detect the presence of a vehicle in the driver's blind spotand to warn the driver should he attempt such a lane change. These blindspot monitors are typically placed on the outside of the vehicle near oron the side rear view mirrors. Since the device is exposed to rain,salt, snow etc., there is a reliability problem resulting from the needto seal the sensor and to permit wires to enter the sensor and also thevehicle. Special wire, for example, should be used to prevent water fromwicking through the wire. These problems as well as similar problemsassociated with other devices which require electric power and which areexposed to the environment, such as forward-mounted airbag crashsensors, can be solved utilizing an inductive coupling techniques ofthis invention.

3.5 Truck-to-Trailer Power and Information Transfer

A serious source of safety and reliability problems results from theflexible wire connections that are necessary between a truck and atrailer. The need for these flexible wire connections and theirassociated connector problems can be eliminated using the inductivecoupling techniques of this invention. In this case, the mere attachmentof the trailer to the tractor automatically aligns an inductive pickupdevice on the trailer with the power lines imbedded in the fifth wheel,for example.

3.6 Wireless Switches

Switches in general do not consume power and therefore they can beimplemented wirelessly according to the teachings of this invention inmany different modes. For a simple on-off switch, a one bit RFID tagsimilar to what is commonly used for protecting against shoplifting instores with a slight modification can be easily implemented. The RFIDtag switch would contain its address and a single accessible bitpermitting the device to be interrogated regardless of its location inthe vehicle without wires. A SAW-based switch as disclosed elsewhereherein can also be used and interrogated wirelessly.

As the switch function becomes more complicated, additional power may berequired and the options for interrogation become more limited. For acontinuously varying switch, for example the volume control on a radio,it may be desirable to use a more complicated design where an inductivetransfer of information is utilized. On the other hand, by usingmomentary contact switches that would set the one bit on only while theswitch is activated and by using the duration of activation, volumecontrol type functions can still be performed even though the switch isremote from the interrogator.

This concept then permits the placement of switches at arbitrarylocations anywhere in the vehicle without regard to the placement ofwires. Additionally, multiple switches can be easily used to control thesame device or a single switch can control many devices.

For example, a switch to control the forward and rearward motion of thedriver seat can be placed on the driver door-mounted armrest andinterrogated by an RFID reader or SAW interrogator located in theheadliner of the vehicle. The interrogator periodically monitors allRFID or SAW switches located in the vehicle which may number over 100.If the driver armrest switch is depressed and the switch bit is changedfrom 0 to 1, the reader knows based on the address or identificationnumber of the switch that the driver intends to operate his seat in aforward or reverse manner. A signal can then be sent over the inductivepower transfer line to the motor controlling the seat and the motor canthus be commanded to move the seat either forward based on one switch IDor backward based on another switch ID. Thus, the switch in the armrestcould actually contain two identification RFIDs or SAW switches, one forforward movement of seat and one for rearward movement of the seat. Assoon the driver ceases operating the switch, the switch state returns to0 and a command is sent to the motor to stop moving the seat. The RFIDor SAW device can be passive or active.

By this process as taught by this invention, all of the 100 or soswitches and other simple sensors can become wireless devices and vastlyreduce the number of wires in a vehicle and increase the reliability andreduce warranty repairs. One such example is the switch that determineswhether the seatbelt is fastened which can now be a wireless switch.

3.7 Wireless Lights

In contrast to switches, lights require power. The power requiredgenerally exceeds that which can be easily transmitted by RF orcapacitive coupling. For lights to become wireless, therefore, inductivecoupling or equivalent can be required. Now, however, it is no longernecessary to have light sockets, wires and connectors. Each light bulbcould be outfitted with an inductive pickup device and a microprocessor.The microprocessor can listen to the information coming over theinductive pickup line, or wirelessly, and when it recognizes itsaddress, it activates an internal switch which turns on the light. Ifthe information is transferred wirelessly, the RFID switch described insection 1.4.4 above can be used. The light bulb becomes a totallysealed, self-contained unit with no electrical connectors or connectionsto the vehicle. It is automatically connected by mounting in a holderand by its proximity, which can be as far away as several inches, to theinductive power line. It has been demonstrated that power transferefficiencies of up to about 99 percent can be achieved by this systemand power levels exceeding about 1 kW can be transferred to a deviceusing a loosely coupled inductive system described above.

This invention therefore considerably simplifies the mounting of lightsin a vehicle since the lights are totally self-contained and not pluggedinto the vehicle power system. Problems associated with sealing thelight socket from the environment disappear vastly simplifying theinstallation of headlights, for example, into the vehicle. The skin ofthe vehicle need not contain any receptacles for a light plug andtherefore there is no need to seal the light bulb edges to prevent waterfrom entering behind the light bulb. Thus, the reliability of vehicleexterior lighting systems is significantly improved. Similarly, the easewith which light bulbs can be changed when they burn out is greatlysimplified since the complicated mechanisms for sealing the light bulbinto the vehicle are no longer necessary. Although headlights werediscussed, the same principles apply to all other lights mounted on avehicle exterior.

Since it is contemplated that the main power transfer wire pair willtravel throughout the automobile in a single branched loop, severallight bulbs can be inductively attached to the inductive wire powersupplier by merely locating a holder for the sealed light bulb within afew inches of the wire. Once again, no electrical connections arerequired.

Consider for example the activation of the right turn signal. Themicroprocessor associated with the turn switch on the steering column isprogrammed to transmit the addresses of the right front and rear turnlight bulbs to turn them on. A fraction of a second later, themicroprocessor sends a signal over the inductive power transfer line, orwirelessly, to turn the light bulbs off. This is repeated for as long asthe turn signal switch is placed in the activation position for a rightturn. The right rear turn signal light bulb receives a message with itsaddress and a bit set for the light to be turned on and it responds byso doing and similarly, when the signal is received for turning thelight off. Once again, all such transmissions occur over a single powerand information inductive line and no wire connections are made to thelight bulb. In this example, all power and information is transferredinductively.

3.8 Keyless Entry

The RFID technology is particularly applicable to keyless entry. Insteadof depressing a button on a remote vehicle door opener, the owner ofvehicle need only carry an RFID card in his pocket. Upon approaching thevehicle door, the reader located in the vehicle door, activates thecircuitry in the RFID card and receives the identification number,checks it and unlocks the vehicle if the code matches. It can even openthe door or trunk based on the time that the driver stands near the dooror trunk. Simultaneously, the vehicle now knows that this is driver No.3, for example, and automatically sets the seat position, headrestposition, mirror position, radio stations, temperature controls and allother driver specific functions including the positions of the petals toadapt the vehicle to the particular driver. When the driver sits in theseat, no ignition key is necessary and by merely depressing a switchwhich can be located anywhere in the vehicle, on the armrest forexample, the vehicle motor starts. The switch can be wireless and thereader or interrogator which initially read the operator's card can beconnected inductively to the vehicle power system.

U.S. Pat. No. 5,790,043 describes the unlocking of a door based on atransponder held by a person approaching the door. By adding thefunction of measuring the distance to the person, by use of thebackscatter from the transponder antenna for example, the distance fromthe vehicle-based transmitter and the person can be determined and thedoor opened when the person is within 5 feet, for example, of the dooras discussed elsewhere herein.

Using the RFID switch discussed above, for example, the integration ofthe keyless entry system with the tire monitor and all other similardevices can be readily achieved.

3.9 In-Vehicle Mesh Network, Intra-Vehicle Communications

The use of wireless networks within a vehicle has been discussedelsewhere herein. Of particular interest here is the use of a meshnetwork (or mesh) wherein the various wireless elements are connectedvia a mesh such that each device can communicate with each other tothereby add information that might aid a particular node. In thesimplest case, nodes on the mesh can merely aid in the transfer ofinformation to a central controller. In more advanced cases, thetemperature monitored by one node can be used by other nodes tocompensate for the effects of temperature on the node operation. Inanother case, the fact that a node has been damaged or is experiencingacceleration can be used to determine the extent of and to forecast theseverity of an accident. Such a mesh network can operate in the discretefrequency or in the ultra wideband mode.

3.10 Road Conditioning Sensing—Black Ice Warning

A frequent cause of accidents is the sudden freezing of roadways orbridge surfaces when the roadway is wet and temperatures are nearfreezing. Sensors exist that can detect the temperature of the roadsurface within less than one degree either by direct measurement or bypassive IR. These sensors can be mounted in locations on the vehiclewhere they have a clear view of the road and thus they are susceptibleto assault from rain, snow, ice, salt etc. The reliability of connectingthese sensors into the vehicle power and information system is thuscompromised. Using the teachings of this invention, black ice warningsensors, for example, can be mounted on the exterior of the vehicle andcoupled into the vehicle power and information system inductively, thusremoving a significant cause of failure of such sensors. Also the use ofappropriate cameras and sensors along with multispectral analysis ofroad surfaces can be particularly useful to discover icing.

Similar sensors can also used to detect the type of roadway on which thecar is traveling. Gravel roads, for example, have typically a lowereffective coefficient of friction than do concrete roads. Knowledge ofthe road characteristics can provide useful information to the vehiclecontrol system and, for example, warn the driver when the speed drivenis above what is safe for the road conditions, including the particulartype of roadway.

3.11 Antennas Including Steerable Antennas

As discussed above, the antennas used in the systems disclosed hereincan contribute significantly to the operation of the systems. In onecase, a silicon or gallium arsenide (for higher frequencies) element canbe placed at an antenna to process the returned signal as needed. Highgain antennas such as the yagi antenna or steerable antennas such aselectronically controllable (or tunable) dielectric constant phasedarray antennas are also contemplated. For steerable antennas, referenceis made to U.S. Pat. No. 6,452,565 “Steerable-beam multiple-feeddielectric resonator antenna”. Also contemplated, in addition to thosediscussed above, are variable slot antennas and Rotman lenses. All ofthese plus other technologies go under the heading of smart antennas andall such antennas are contemplated herein.

The antenna situation can be improved as the frequency increases.Currently, SAW devices are difficult to make that operate much aboveabout 2.4 GHz. It is expected that as lithography systems improve thateventually these devices will be made to operate in the higher GHz rangepermitting the use of antennas that are even more directional.

3.12 Other Miscellaneous Sensors

Many new sensors are now being adapted to an automobile to increase thesafety, comfort and convenience of vehicle occupants. Each of thesensors currently requires separate wiring for power and informationtransfer. Under the teachings of this invention, these separate wirescan become unnecessary and sensors could be added at will to theautomobile at any location within a few inches of the inductive powerline system or, in some cases, within range of an RF interrogator. Evensensors that were not contemplated by the vehicle manufacturer can beadded later with a software change to the appropriate vehicle CPU asdiscussed above.

Such sensors include heat load sensors that measure the sunlight comingin through the windshield and adjust the environmental conditions insidethe vehicle or darken the windshield to compensate. Seatbelt sensorsthat indicate that the seatbelt is buckled and the tension oracceleration experienced by the seatbelt can now also use RFID and/orSAW technology as can low power microphones. Door-open or door-ajarsensors also can use the RFID and/or SAW technology and would not needto be placed near an inductive power line. Gas tank fuel level and otherfluid level sensors which do not require external power and are nowpossible thus eliminating any hazard of sparks igniting the fuel in thecase of a rear impact accident which ruptures the fuel tank, forexample.

Capacitive proximity sensors that measure the presence of a life formwithin a few meters of the automobile can be coupled wirelessly to thevehicle. Cameras or other vision or radar or lidar sensors that can bemounted external to the vehicle and not require unreliable electricalconnections to the vehicle power system permitting such sensors to betotally sealed from the environment are also now possible. Such sensorscan be based on millimeter wave radar, passive or active infrared, oroptical or any other portion of the electromagnetic spectrum that issuitable for the task. Radar, passive sound or ultrasonic backup sensorsor rear impact anticipatory sensors also are now feasible withsignificantly greater reliability.

The use of passive audio requires additional discussion. One or moredirectional microphones aimed from the rear of the vehicle can determinefrom tire-produced audio signals, for example, that a vehicle isapproaching and might impact the target vehicle which contains thesystem. The target vehicle's tires as well as those to the side of thetarget vehicle will also produce sounds which need to be cancelled outof the sound from the directional microphones using well-known noisecancellation techniques. By monitoring the intensity of the sound incomparison with the intensity of the sound from the target vehicle's owntires, a determination of the approximate distance between the twovehicles can be made. Finally, a measurement of the rate of change insound intensity can be used to estimate the time to collision. Thisinformation can then be used to pre-position the headrest, for example,or other restraint device to prepare the occupants of the target vehiclefor the rear end impact and thus reduce the injuries therefrom. Asimilar system can be used to forecast impacts from other directions. Insome cases, the microphones will need to be protected in a manner so asto reduce noise from the wind such as with a foam protection layer. Thissystem provides a very inexpensive anticipatory crash system.

Previously, the use of radio frequency to interrogate an RFID tag hasbeen discussed. Other forms of electromagnetic radiation are possible.For example, an infrared source can illuminate an area inside thevehicle and a pin diode or CMOS camera can receive reflections fromcorner cube or dihedral corner (as more fully described below)reflectors located on objects that move within the vehicle. Theseobjects would include items such as the seat, seatback, and headrest.Through this technique, the time of flight, by pulse or phase lock looptechnologies, can be measured or modulated IR radiation and phasemeasurements can be used to determine the distance to each of the cornercube or dihedral corner reflectors.

The above discussion has concentrated on applications primarily insideof the vehicle (although mention is often made of exterior monitoringapplications). There are also a significant number of applicationsconcerning the interaction of a vehicle with its environment. Althoughthis might be construed as a deviation from the primary premise of thisinvention, which is that the device is either powerless in the sensethat no power is required other than perhaps that which can be obtainedfrom a radio frequency signal or a powered device and where the power isobtained through induction coupling, it is encompassed within theinvention.

When looking exterior to the vehicle, devices that interact with thevehicle may be located sufficiently far away that they will requirepower and that power cannot be obtained from the automobile. In thediscussion below, two types of such devices will be considered, thefirst type which does not require infrastructure-supplied power and thesecond which does.

A rule of thumb is that an RFID tag of normal size that is located morethan about a meter away from the reader or interrogator must have aninternal power source. Exceptions to this involve cases where the onlyinformation that is transferred is due to the reflection off of a radarreflector-type device and for cases where the tag is physically larger.For those cases, a purely passive RFID can be five and sometimes moremeters away from the interrogator. Nevertheless, we shall assume that ifthe device is more than a few meters away that the device must containsome kind of power supply.

An interesting application is a low-cost form of adaptive cruise controlor forward collision avoidance system. In this case, a purely passiveRFID tag could be placed on every rear license plate in a particulargeographical area, such as a state. The subject vehicle would containtwo readers, one on the forward left side of the vehicle and one on theforward right side. Upon approaching the rear of a car having the RFIDlicense plate, the interrogators in the vehicle would be able todetermine the distance, by way of reflected signal time of flight, fromeach reader to the license plate transducer. If the license plate RFIDis passive, then the range is limited to about 5 meters depending on thesize of the tag. Nevertheless, this will be sufficient to determine thatthere is a vehicle in front of or to the right or left side of thesubject vehicle. If the relative velocity of the two vehicles is suchthat a collision will occur, the subject vehicle can automatically haveits speed altered so as to prevent the collision, typically a rear endcollision. Alternately, the front of the vehicle can have twospaced-apart tags in which case, a single interrogator could suffice.

An explanation is found in the parent '240 application and thisinnovation leads to a novel addition or substitution to putting an RFIDtag onto a license plate is to emboss the license plate or otherwiseattach to it or elsewhere on the vehicle a corner cube or dihedralcorner reflector which can yield a bright reflection from a radar orladar (laser radar) transmitter from a following vehicle, for example.Further, the reflector can be designed to rotate the polarization of abeam by 90 degrees, thus the potential problem of the receiver beingblinded by another vehicle's system is reduced. Additionally, areflector can be designed as described above to reflect a polarized beamfrom a non-polarized beam or better to rotate a polarized beam throughan arbitrary angle. In this manner, some information about the vehiclesuch as its mass class can be conveyed to the interrogating vehicle. Apolarization on only 0 degrees can signify a passenger car, only 90degrees an SUV or other large passenger vehicle or pickup truck, 45degrees a small truck, both 0 and 45 degrees (using two reflectors) alarger truck, 45 and 90 degrees a larger truck etc. yielding 7 or moreclassifications. Thus using a very low cost reflector, a great deal ofinformation can be conveyed including the range to the vehicle based ontime-of-flight or phase angle comparison if the transmitted beam ismodulated. Noise or pseudo-noise modulated radar would also beapplicable as a modulation based system for distance measurement.

Additions to an RFID-based system that can be used alone or along withthe reflector system discussed above include the addition of an energyharvesting system such as solar power or power from vibrations. Thus thetag can start out as a pure passive tag providing up to about 10 metersrange and grow to an active tag providing a 30 or more meter range. Withthe use of RFID, a great deal of additional information can betransmitted such as the vehicle weight, license plate number, tolling IDetc. Once a tire pressure interrogator as discussed above is on thevehicle, the cost to add one or more license plate interrogatingantennas is small and the cost addition to a license plate can be as lowas 1-5 US dollars. Since no electrical connection need be made to thevehicle, the installation cost is no more than for an ordinary licenseplate.

An alternate approach is to visually scan license plates using an imagersuch as a camera. An infrared imager and a source of infraredillumination can be used. Using such a system, the characters (numbersand letters) can be read and if the license plate-issuing authority hascoded the properties (type of vehicle, weight, etc.) into thesecharacters, a vehicle can identify those properties of a vehicle that itmay soon impact and that information can be a factor in the vehiclecontrol algorithm or restraint deployment decision.

Systems are under development that will permit an automobile todetermine its absolute location on the surface of the earth. Thesesystems are being developed in conjunction with intelligenttransportation systems. Such location systems are frequently based ondifferential GPS (DGPS). One problem with such systems is that theappropriate number of GPS satellites is not always within view of theautomobile. For such cases, it is necessary to have an earth-basedsystem which will provide the information to the vehicle permitting itto absolutely locate itself within a few centimeters. One such systemcan involve the use of RFID tags placed above, adjacent or below thesurface of the highway.

For the cases where the RFID tags are located more than a few metersfrom the vehicle, a battery or other poser source will probably berequired and this will be discussed below. For the systems withoutbatteries, such as placing the RFID tag in the concrete, with tworeaders located one on each side of the vehicle, the location of the tagembedded in the concrete can be precisely determine based on the time offlight of the radar pulse from the readers to the tag and back. Usingthis method, the precise location of the vehicle relative to a tagwithin a few centimeters can be readily determined and since theposition of the tag will be absolutely known by virtue of an in-vehicleresident digital map, the position of the vehicle can be absolutelydetermined regardless of where the vehicle is. For example, if thevehicle is in a tunnel, then it will know precisely its location fromthe RFID pavement embedded tags. Note that the polarization rotationreflector discussed above will also perform this task excellently.

It is also possible to determine the relative velocity of the vehiclerelative to the RFID tag or reflector using the Doppler Effect based onthe reflected signals. For tags located on license plates or elsewhereon the rear of vehicles, the closing velocity of the two vehicles can bedetermined and for tags located in or adjacent to the highway pavement,the velocity of the vehicle can be readily determined. The velocity canin both cases be determined based on differentiating two distancemeasurements.

In many cases, it may be necessary to provide power to the RFID tagsince the distance to the vehicle will exceed a few meters. This iscurrently being used in reverse for automatic tolling situations wherethe RFID tag is located on the vehicle and interrogated using readerslocated at the toll both.

When the RFID tag to be interrogated by vehicle-mounted readers is morethan a few meters from the vehicle, the tag in many cases must besupplied with power. This power can come from a variety of sourcesincluding a battery which is part of the device, direct electricalconnections to a ground wire system, solar batteries, generators thatgenerate power from vehicle or component vibration, other forms ofenergy harvesting or inductive energy transfer from a power line.

For example, if an RFID tag were to be placed on a light post indowntown Manhattan, sufficient energy could be obtained from aninductive pickup from the wires used to power the light to recharge abattery in the RFID. Thus, when the lights are turned on at night, theRFID battery could be recharged sufficiently to provide power foroperation 24 hours a day. In other cases, a battery or ultracapacitorcould be included in the device and replacement or recharge of thebattery would be necessitated periodically, perhaps once every twoyears.

An alternate approach to having a vehicle transmit a pulse to the tagand wait for a response, would be to have the tag periodically broadcasta few waves of information at precise timing increments. Then, thevehicle with two receivers could locate itself accurately relative tothe earth-based transmitter.

For example, in downtown Manhattan, it would be difficult to obtaininformation from satellites that are constantly blocked by tallbuildings. Nevertheless, inexpensive transmitters could be placed on avariety of lampposts that would periodically transmit a pulse to allvehicles in the vicinity. Such a system could be based on a broadbandmicropower impulse radar system as disclosed in several U.S. patents.Alternately, a narrow band signal can be used.

Once again, although radar type microwave pulses have been discussed,other portions of the electromagnetic spectrum can be utilized. Forexample, a vehicle could send a beam of modulated infrared towardinfrastructure-based devices such as poles which contain corner orpolarization modifying reflectors. The time of flight of IR radiationfrom the vehicle to the reflectors can be accurately measured and sincethe vehicle would know, based on accurate maps, where the reflector islocated, there is the little opportunity for an error.

The invention is also concerned with wireless devices that containtransducers. An example is a temperature transducer coupled withappropriate circuitry which is capable of receiving power eitherinductively or through radio frequency energy transfer or even, and somecases, capacitively. Such temperature transducers may be used to measurethe temperature inside the passenger compartment or outside of thevehicle. They also can be used to measure the temperature of somecomponent in the vehicle, e.g., the tire. A distinctive feature of someembodiments of this invention is that such temperature transducers arenot hard-wired into the vehicle and do not rely solely on batteries.Such temperature sensors have been used in other environments such asthe monitoring of the temperature of domestic and farm animals forhealth monitoring purposes.

Upon receiving power inductively or through the radio frequency energytransfer, the temperature transducer conducts its temperaturemeasurement and transmits the detected temperature to a process orcentral control module in the vehicle.

The wireless communication within a vehicle can be accomplished inseveral ways. The communication can be through the same path thatsupplies power to the device, or it can involve the transmission ofwaves that are received by another device in the vehicle. These wavescan be either electromagnetic (radio frequency, microwave, infrared,etc) or ultrasonic. If electromagnetic, they can be sent using a varietyof protocols such as CDMA, FDMA, TDMA or ultrawideband (see, e.g.,Hiawatha Bray, “The next big thing is actually ultrawide”, Boston Globe,Jun. 25, 2004).

Many other types of transducers or sensors can be used in this manner.The distance to an object from a vehicle can be measured using a radarreflector type RFID (Radio Frequency Identification) tag which permitsthe distance to the tag to be determined by the time of flight of radiowaves. Another method of determining distance to an object can bethrough the use of ultrasound wherein the device is commanded to emit anultrasonic burst and the time required for the waves to travel to areceiver is an indication of the displacement of the device from thereceiver.

Although in most cases the communication will take place within thevehicle, and some cases such as external temperature transducers or tirepressure transducers, the source of transmission will be located outsideof the compartment of the vehicle.

A discussion of RFID technology including its use for distancemeasurement is included in the RFID Handbook, by Klaus Finkenzeller,John Wiley & Sons, New York 1999.

In one simple form, the invention can involve a single transducer andsystem for providing power and receiving information. An example of sucha device would be an exterior temperature monitor which is placedoutside of the vehicle and receives its power and transmits itsinformation through the windshield glass. At the other extreme, a pairof parallel wires carrying high frequency alternating current can travelto all parts of the vehicle where electric power is needed. In thiscase, every device could be located within a few inches of this wirepair and through an appropriately designed inductive pickup system, eachdevice receives the power for operation inductively from the wire pair.A system of this type which is designed for use in powering vehicles isdescribed in several U.S. patents listed above.

In this case, all sensors and actuators on the vehicle can be powered bythe inductive power transfer system. The communication with thesedevices could either be over the same system or, alternately, could betake place via RF, ultrasound, infrared or other similar communicationsystem. If the communication takes place either by RF or over amodulated wire system, a protocol such as the Bluetooth™ or Zigbeeprotocol can be used. Other options include the Ethernet and token ringprotocols.

The above system technology is frequently referred to as loosely coupledinductive systems. Such systems have been used for powering a vehicledown a track or roadway but have not been used within the vehicle. Theloosely coupled inductive system makes use of high frequency (typically10,000 Hz) and resonant circuits to achieve a power transfer approaching99 percent efficiency. The resonant system is driven using a switchingamplifier. As discussed herein, this is believed to be the first exampleof a high frequency power system for use within vehicles.

Every device that utilizes the loosely coupled inductive system wouldcontain a microprocessor and thus would be considered a smart device.This includes every light, switch, motor, transducer, sensor etc. Eachdevice could have an address and would respond only to informationcontaining its address.

It is now contemplated that the power systems for next generationautomobiles and trucks will change from the current standard of 12 voltsto a new standard of 42 volts. The power generator or alternator in suchvehicles will produce alternating current and thus will be compatiblewith the system described herein wherein all power within the vehiclewill be transmitted using AC.

It is contemplated that some devices will require more power than can beobtained instantaneously from the inductive, capacitive or radiofrequency source. In such cases, batteries, capacitors orultra-capacitors may be used directly associated with a particulardevice to handle peak power requirements. Such a system can also be usedwhen the device is safety critical and there is a danger of disruptionof the power supply during a vehicle crash, for example. In general, thebattery or capacitor would be charged when the device is not beingpowered.

In some cases, the sensing device may be purely passive and require nopower. One such example is when an infrared or optical beam of energy isreflected off of a passive reflector to determine the distance to thatreflector. Another example is a passive reflective RFID tag.

As noted above, several U.S. patents describe arrangements formonitoring the pressure inside a rotating tire and to transmit thisinformation to a display inside the vehicle. A preferred approach formonitoring the pressure within a tire is to instead monitor thetemperature of the tire using a temperature sensor and associated powersupplying circuitry as discussed above and to compare that temperatureto the temperature of other tires on the vehicle, as discussed above.When the pressure within a tire decreases, this generally results in thetire temperature rising if the vehicle load is being carried by thattire. In the case where two tires are operating together at the samelocation such as on a truck trailer, just the opposite occurs. That is,the temperature of the fully inflated tire can increase since it is nowcarrying more load than the partially inflated tire.

4. Summary

As stated at the beginning this application is one in a series ofapplications covering safety and other systems for vehicles and otheruses. The disclosure herein goes beyond that needed to support theclaims of the particular invention that is being claimed herein. This isnot to be construed that the inventors are releasing the unclaimeddisclosure and subject matter into the public domain. Rather, it isintended that patent applications have been or will be filed to coverall of the subject matter disclosed above.

The inventions described above are, of course, susceptible to manyvariations, combinations of disclosed components, modifications andchanges, all of which are within the skill of the art. It should beunderstood that all such variations, modifications and changes arewithin the spirit and scope of the inventions and of the appendedclaims. Similarly, it will be understood that applicants intend to coverand claim all changes, modifications and variations of the examples ofthe preferred embodiments of the invention herein disclosed for thepurpose of illustration which do not constitute departures from thespirit and scope of the present invention as claimed.

Although several preferred embodiments are illustrated and describedabove, there are possible combinations using other geometries, sensors,materials and different dimensions for the components that perform thesame functions. This invention is not limited to the above embodimentsand should be determined by the following claims.

1. An electrical system in a vehicle, comprising crash sensor means forsensing a crash involving the vehicle; occupant protection means forprotecting an occupant in the event of a crash involving the vehicle;and a single bus consisting of a pair of wires, said crash sensor meansand said occupant protection means being connected to said bus and beingsupplied with power by said bus and communication through said bus, saidoccupant protection means being actuated in the event of a crashinvolving the vehicle as sensed by said crash sensor means.
 2. Thesystem of claim 1, wherein said occupant protection means comprise anoccupant protection device and a power supply for providing power toenable actuation of said occupant protection device.
 3. The system ofclaim 2, wherein said occupant protection means comprise a housing, saidoccupant protection device being arranged in said housing, said powersupply being a capacitor arranged in said housing.
 4. The system ofclaim 1, wherein said occupant protection means comprise an occupantprotection device and an occupant sensor arranged to obtain data aboutoccupancy of the vehicle for use in determining actuation of saidoccupant protection device.
 5. The system of claim 1, wherein saidoccupant protection means comprise an airbag, a module including anoccupant position sensor arranged to obtain data about the position ofan occupant to be protected upon inflation of said airbag, and acontroller coupled to said occupant position sensor for controllingdeployment and inflation of said airbag based on the position of theoccupant, said controller being arranged in said module, adjacent saidmodule or proximate said module.
 6. The system of claim 1, wherein saidoccupant protection means comprise an airbag, a housing, and acontroller for controlling deployment and inflation of said airbag. 7.The system of claim 1, wherein said bus is arranged to provide a signalindicative of a crash involving the vehicle as obtained from said crashsensor means, said occupant protective means being arranged to receivethe signal and independently determine whether to actuate an occupantprotection device.
 8. The system of claim 1, wherein said occupantprotection means comprises diagnostic electronics for diagnosingfunctionality of said occupant protection means, further comprising acentral diagnostic module connected to said bus, said diagnosticelectronics of said occupant protection means being arranged to providean indication of the functionality thereof to said central diagnosticmodule, said central diagnostic module being arranged to provide anindication of the functionality of all of said at least one occupantprotection system to a display visible to an occupant of the vehicle. 9.The system of claim 1, wherein said crash sensor means is arranged togenerate and send a coded signal over said bus to said occupantprotection means, the coded signal being indicative of a sensed crashcondition.
 10. The system of claim 1, wherein said occupant protectionmeans comprises a plurality of occupant protection systems, each of saidoccupant protection systems being assigned an address, said bus beingarranged to transfer data in the form of messages each having an addressof at least one of said occupant protection systems such that only saidat least one of said occupant protection systems assigned to saidaddress is responsive to said message having said address, each of saidoccupant protection systems being arranged to determine whether messageson said bus include said address assigned to said occupant protectionsystem.
 11. An electrical system in a vehicle, comprising a plurality ofcrash sensor means for sensing different types of crashes involving thevehicle; a plurality of occupant protection systems each including anoccupant protection device arranged to protect an occupant in the eventof a crash involving the vehicle; a first bus, a discrete portion ofsaid crash sensor means and a discrete portion of said occupantprotection systems being coupled to said first bus and being suppliedwith power by said first bus and communication through said first bus,each of said occupant protection devices being actuatable in the eventof a crash involving the vehicle as sensed by one of said crash sensormeans; and a second bus, a different discrete portion of said crashsensor means and a discrete portion of said occupant protection systemsbeing coupled to said second bus and being supplied with power by saidsecond bus and communication through said second bus, each of saidoccupant protection devices being actuatable in the event of a crashinvolving the vehicle as sensed by one of said crash sensor means, eachof said crash sensor means and each of said occupant protection systemsbeing either coupled to said first bus or to said second bus.
 12. Thesystem of claim 11, wherein each of said occupant protection systemscomprises a power supply for providing power to enable actuation of saidoccupant protection device.
 13. The system of claim 12, wherein each ofsaid occupant protection systems comprises a housing, said occupantprotection device being arranged in said housing, said power supplybeing a capacitor arranged in said housing.
 14. The system of claim 11,wherein each of said occupant protection systems comprises an occupantsensor arranged to obtain data about occupancy of the vehicle for use indetermining actuation of said occupant protection device.
 15. The systemof claim 11, wherein said occupant protection device is an airbag, eachof said occupant protection systems comprising a module including anoccupant position sensor arranged to obtain data about the position ofan occupant to be protected upon inflation of said airbag, each of saidoccupant protection systems further comprising a controller coupled tosaid occupant position sensor for controlling deployment and inflationof said airbag based on the position of the occupant, said controllerbeing arranged in said module, adjacent said module or proximate saidmodule.
 16. The system of claim 11, wherein each of said occupantprotection systems comprises a housing, said occupant protection devicebeing an airbag, each of said occupant protection systems furthercomprising a controller for controlling deployment and inflation of saidairbag.
 17. The system of claim 11, wherein said first and second busesare arranged to provide a signal indicative of a crash involving thevehicle as obtained from one of said crash sensor means coupled thereto,each of said occupant protection systems on the respective one of saidfirst and second buses being arranged to receive the signal andindependently determine whether to actuate said occupant protectiondevice.
 18. The system of claim 11, wherein each of said occupantprotection systems comprises diagnostic electronics for diagnosingfunctionality of said occupant protection system, further comprising acentral diagnostic module connected to each of said first and secondbuses, said diagnostic electronics of each of said occupant protectionsystems being arranged to provide an indication of the functionalitythereof to the respective one of said central diagnostic modules, saidcentral diagnostic module being arranged to provide an indication of thefunctionality of all of said occupant protection systems to a displayvisible to an occupant of the vehicle.
 19. The system of claim 11,wherein said crash sensor means are arranged to generate and send acoded signal over said first or second bus to which it is coupled, thecoded signal being indicative of a sensed crash condition.
 20. Thesystem of claim 11, wherein each of said occupant protection systems isassigned an address, said first and second buses being arranged totransfer data in the form of messages each having an address of at leastone of said occupant protection systems such that only said at least oneof said occupant protection systems assigned to said address isresponsive to said message having said address, each of said occupantprotection systems being arranged to determine whether messages on saidfirst or second bus include said address assigned to said occupantprotection system.